Sky calendar
The next 18 months of things that happen on a date, solved from the ephemeris rather than kept in a list. Almost every one is the same instant for everybody on Earth, so a date here needs no location to be true — what is visible tonight is the list that does depend on where you are standing.
Coming up
] SOONEST FIRST- CONJUNCTIONIN 4 DAYS8TUE
The Moon 46′ from Jupiter
46′ between the Moon and Jupiter — one binocular field, before dawn.
- MOONIN 6 DAYS11FRI
New moon
No Moon in the night sky: the darkest week of the month.
- CONJUNCTIONIN 10 DAYS14MON
The Moon 29′ from Venus
29′ between the Moon and Venus — one binocular field, after sunset.
+WHAT THE EIGHT KINDS ARE
- Eclipses — solar and lunar, with where on Earth each is greatest.
- Meteor showers — dated by where the Earth is in its orbit, not by a fixed calendar day.
- Moon phases — the four quarters, which set what else is worth chasing that fortnight.
- Close pairings — two bright things within a few degrees of each other.
- Oppositions — the night each outer planet is closest, biggest and up all night.
- Elongations — the mornings and evenings Mercury and Venus stand furthest from the Sun.
- Equinoxes and solstices — the four turning points of the year.
- Flybys — near-Earth asteroids passing inside twenty lunar distances.
Pick a place and every event will say which hours are worth being outside for it. Until you do, nothing here is answered for anywhere in particular.
September 2026
] 6 EVENTS- 8TUECONJUNCTION--:--
The Moon 46′ from Jupiter
The Moon passes 46′ from Jupiter — close enough that a thumb held at arm's length covers both at once, and a pair of binoculars holds them in one field. Look before dawn; the Moon moves its own width every hour, so the gap looks noticeably different either side of tonight.
+WHAT TO EXPECTCLOSE
- SEPARATION
- 0.8° — about a finger-width at arm's length
- FROM THE SUN
- 31° — the angle between it and the Sun in our sky
Close enough to fit in the same telescope field, which is a rarer sight than either object alone. Binoculars show it comfortably; the naked eye sees two things almost touching. Look on the evenings either side too — they will still be close, and one of the two nights is usually the clearer.
- 11FRIMOON--:--
New moon
The Moon is between us and the Sun, so it is up all day and invisible all night — which makes this the darkest sky of the month and the best fortnight of it for faint galaxies and nebulae.
+WHAT TO EXPECTCLOSE
There is nothing to look at, which is the point: this is the fortnight to go after galaxies, nebulae and the Milky Way, and the week either side of it is the darkest sky you will get this month. Take the faintest thing on your list.
- 14MONCONJUNCTION--:--
The Moon 29′ from Venus
The Moon passes 29′ from Venus — close enough that a thumb held at arm's length covers both at once, and a pair of binoculars holds them in one field. Look after sunset; the Moon moves its own width every hour, so the gap looks noticeably different either side of tonight.
+WHAT TO EXPECTCLOSE
- SEPARATION
- 0.5° — about half a finger-width at arm's length
- FROM THE SUN
- 41° — the angle between it and the Sun in our sky
Close enough to fit in the same telescope field, which is a rarer sight than either object alone. Binoculars show it comfortably; the naked eye sees two things almost touching. Look on the evenings either side too — they will still be close, and one of the two nights is usually the clearer.
- 18FRIMOON--:--
First quarter
Half the disc is lit and the Moon sits high in the evening, with the sunrise line running down its middle — the shadows along that line are long, which is when its craters look their most three-dimensional in any telescope.
+WHAT TO EXPECTCLOSE
A small telescope on the line between light and dark, which is where the shadows are longest and the craters look carved rather than printed. Any evening within a night or two of this shows much the same thing.
- 26SATOPPOSITION--:--
Neptune at opposition
Neptune is directly opposite the Sun from here, so it rises as the Sun sets, stands highest at midnight and sets at sunrise. It is also about as close to Earth as it gets this time round, which makes this its brightest and biggest night of the year — the one to point a telescope at it.
+WHAT TO EXPECTCLOSE
- FROM THE SUN
- 180° — opposite the Sun, so up all night
It rises as the Sun sets and is highest in the middle of the night, which is when to look: the higher it is, the less air is in the way and the steadier the view. Any telescope will show the disc, and a night either side of this date is indistinguishable from the date itself.
- 26SATMOON--:--
Full moon
The Moon rises as the Sun sets and is up all night, fully lit. It is the best night of the month to look at the Moon and the worst to look at anything faint, because its light scatters through the whole sky.
+WHAT TO EXPECTCLOSE
Any eye, any binoculars, any telescope — and better through binoculars than most people expect. The one thing a full moon is bad for is the full moon itself: with the Sun straight behind us there are no shadows on the disc, so it is bright and flat. The craters look their best a week either side of tonight.
October 2026
] 8 EVENTS- 3SATMOON--:--
Last quarter
Half lit again, and now rising around midnight — so the early evening is dark and the small hours are not, the reverse of the first quarter.
+WHAT TO EXPECTCLOSE
A small telescope on the line between light and dark, which is where the shadows are longest and the craters look carved rather than printed. Any evening within a night or two of this shows much the same thing.
- 4SUNOPPOSITION--:--
Saturn at opposition
Saturn is directly opposite the Sun from here, so it rises as the Sun sets, stands highest at midnight and sets at sunrise. It is also about as close to Earth as it gets this time round, which makes this its brightest and biggest night of the year — the one to point a telescope at it.
+WHAT TO EXPECTCLOSE
- FROM THE SUN
- 180° — opposite the Sun, so up all night
It rises as the Sun sets and is highest in the middle of the night, which is when to look: the higher it is, the less air is in the way and the steadier the view. Any telescope will show the disc, and a night either side of this date is indistinguishable from the date itself.
- 5MONCONJUNCTION--:--
The Moon 1.1° from Mars
The Moon passes 1.1° from Mars — close enough that a thumb held at arm's length covers both at once, and a pair of binoculars holds them in one field. Look before dawn; the Moon moves its own width every hour, so the gap looks noticeably different either side of tonight.
+WHAT TO EXPECTCLOSE
- SEPARATION
- 1.1° — about a finger-width at arm's length
- FROM THE SUN
- 68° — the angle between it and the Sun in our sky
A naked-eye sight rather than a telescope one: the two are far enough apart that magnifying them separates them. Binoculars frame the pair nicely. The nights either side are nearly as good, so cloud on the night itself is not the end of it.
- 6TUECONJUNCTION--:--
The Moon 10′ from Jupiter
10′ between the Moon and Jupiter — one binocular field, before dawn.
+WHAT TO EXPECTCLOSE
- SEPARATION
- 0.2° — about half a finger-width at arm's length
- FROM THE SUN
- 53° — the angle between it and the Sun in our sky
Close enough to fit in the same telescope field, which is a rarer sight than either object alone. Binoculars show it comfortably; the naked eye sees two things almost touching. Look on the evenings either side too — they will still be close, and one of the two nights is usually the clearer.
- 10SATMOON--:--
New moon
No Moon in the night sky: the darkest week of the month.
+WHAT TO EXPECTCLOSE
There is nothing to look at, which is the point: this is the fortnight to go after galaxies, nebulae and the Milky Way, and the week either side of it is the darkest sky you will get this month. Take the faintest thing on your list.
- 12MONELONGATION--:--
Mercury at its furthest from the Sun (evening sky)
Mercury stands 25° away from the Sun in our sky today, the widest that gap opens on this pass. Look west just after sunset: this is the easiest Mercury gets to find, and Mercury is hard to catch at any other time.
+WHAT TO EXPECTCLOSE
- FROM THE SUN
- 25° — the angle between it and the Sun in our sky
Look low, into the twilight, and start before you think you need to — the planet is bright enough to find in a colouring sky and hard to find once the sky is properly dark, because by then it is setting. Binoculars help you catch it first; an unobstructed horizon in that direction matters more than any equipment.
- 18SUNMOON--:--
First quarter
Half lit and high in the evening — the best week for lunar craters.
+WHAT TO EXPECTCLOSE
A small telescope on the line between light and dark, which is where the shadows are longest and the craters look carved rather than printed. Any evening within a night or two of this shows much the same thing.
- 26MONMOON--:--
Full moon
Up all night and fully lit — bright sky, nothing faint gets through.
+WHAT TO EXPECTCLOSE
Any eye, any binoculars, any telescope — and better through binoculars than most people expect. The one thing a full moon is bad for is the full moon itself: with the Sun straight behind us there are no shadows on the disc, so it is bright and flat. The craters look their best a week either side of tonight.
November 2026
] 11 EVENTS- 1SUNMOON--:--
Last quarter
Half lit, rising near midnight — dark evenings, bright small hours.
+WHAT TO EXPECTCLOSE
A small telescope on the line between light and dark, which is where the shadows are longest and the craters look carved rather than printed. Any evening within a night or two of this shows much the same thing.
- 2MONCONJUNCTION--:--
The Moon 58′ from Mars
58′ between the Moon and Mars — one binocular field, before dawn.
+WHAT TO EXPECTCLOSE
- SEPARATION
- 1.0° — about a finger-width at arm's length
- FROM THE SUN
- 81° — the angle between it and the Sun in our sky
Close enough to fit in the same telescope field, which is a rarer sight than either object alone. Binoculars show it comfortably; the naked eye sees two things almost touching. Look on the evenings either side too — they will still be close, and one of the two nights is usually the clearer.
- 2MONCONJUNCTION--:--
The Moon 29′ from Jupiter
29′ between the Moon and Jupiter — one binocular field, before dawn.
+WHAT TO EXPECTCLOSE
- SEPARATION
- 0.5° — about half a finger-width at arm's length
- FROM THE SUN
- 76° — the angle between it and the Sun in our sky
Close enough to fit in the same telescope field, which is a rarer sight than either object alone. Binoculars show it comfortably; the naked eye sees two things almost touching. Look on the evenings either side too — they will still be close, and one of the two nights is usually the clearer.
- 7SATCONJUNCTION--:--
The Moon 57′ from Venus
57′ between the Moon and Venus — one binocular field, before dawn.
+WHAT TO EXPECTCLOSE
- SEPARATION
- 0.9° — about a finger-width at arm's length
- FROM THE SUN
- 22° — the angle between it and the Sun in our sky
Close enough to fit in the same telescope field, which is a rarer sight than either object alone. Binoculars show it comfortably; the naked eye sees two things almost touching. Look on the evenings either side too — they will still be close, and one of the two nights is usually the clearer.
- 9MONMOON--:--
New moon
No Moon in the night sky: the darkest week of the month.
+WHAT TO EXPECTCLOSE
There is nothing to look at, which is the point: this is the fortnight to go after galaxies, nebulae and the Milky Way, and the week either side of it is the darkest sky you will get this month. Take the faintest thing on your list.
- 16MONCONJUNCTION--:--
Mars and Jupiter 1.2° apart
Mars and Jupiter come within 1.2° of each other, close enough to take in with one glance and to frame together in binoculars. They are 88° from the Sun, so look east before sunrise.
+WHAT TO EXPECTCLOSE
- SEPARATION
- 1.2° — about a finger-width at arm's length
- FROM THE SUN
- 88° — the angle between it and the Sun in our sky
A naked-eye sight rather than a telescope one: the two are far enough apart that magnifying them separates them. Binoculars frame the pair nicely. The nights either side are nearly as good, so cloud on the night itself is not the end of it.
- 17TUEMOON--:--
First quarter
Half lit and high in the evening — the best week for lunar craters.
+WHAT TO EXPECTCLOSE
A small telescope on the line between light and dark, which is where the shadows are longest and the craters look carved rather than printed. Any evening within a night or two of this shows much the same thing.
- 20FRIELONGATION--:--
Mercury at its furthest from the Sun (morning sky)
Mercury stands 20° away from the Sun in our sky today, the widest that gap opens on this pass. Look east shortly before sunrise: this is the easiest Mercury gets to find, and Mercury is hard to catch at any other time.
+WHAT TO EXPECTCLOSE
- FROM THE SUN
- 20° — the angle between it and the Sun in our sky
Look low, into the twilight, and start before you think you need to — the planet is bright enough to find in a colouring sky and hard to find once the sky is properly dark, because by then it is setting. Binoculars help you catch it first; an unobstructed horizon in that direction matters more than any equipment.
- 24TUEMOON--:--
Full moon
Up all night and fully lit — bright sky, nothing faint gets through.
+WHAT TO EXPECTCLOSE
Any eye, any binoculars, any telescope — and better through binoculars than most people expect. The one thing a full moon is bad for is the full moon itself: with the Sun straight behind us there are no shadows on the disc, so it is bright and flat. The craters look their best a week either side of tonight.
- 25WEDOPPOSITION--:--
Uranus at opposition
Uranus is directly opposite the Sun from here, so it rises as the Sun sets, stands highest at midnight and sets at sunrise. It is also about as close to Earth as it gets this time round, which makes this its brightest and biggest night of the year — the one to point a telescope at it.
+WHAT TO EXPECTCLOSE
- FROM THE SUN
- 180° — opposite the Sun, so up all night
It rises as the Sun sets and is highest in the middle of the night, which is when to look: the higher it is, the less air is in the way and the steadier the view. Any telescope will show the disc, and a night either side of this date is indistinguishable from the date itself.
- 30MONCONJUNCTION--:--
The Moon 1.1° from Jupiter
1.1° between the Moon and Jupiter — one binocular field, before dawn.
+WHAT TO EXPECTCLOSE
- SEPARATION
- 1.1° — about a finger-width at arm's length
- FROM THE SUN
- 102° — the angle between it and the Sun in our sky
A naked-eye sight rather than a telescope one: the two are far enough apart that magnifying them separates them. Binoculars frame the pair nicely. The nights either side are nearly as good, so cloud on the night itself is not the end of it.
December 2026
] 6 EVENTS- 1TUEMOON--:--
Last quarter
Half lit, rising near midnight — dark evenings, bright small hours.
+WHAT TO EXPECTCLOSE
A small telescope on the line between light and dark, which is where the shadows are longest and the craters look carved rather than printed. Any evening within a night or two of this shows much the same thing.
- 9WEDMOON--:--
New moon
No Moon in the night sky: the darkest week of the month.
+WHAT TO EXPECTCLOSE
There is nothing to look at, which is the point: this is the fortnight to go after galaxies, nebulae and the Milky Way, and the week either side of it is the darkest sky you will get this month. Take the faintest thing on your list.
- 17THUMOON--:--
First quarter
Half lit and high in the evening — the best week for lunar craters.
+WHAT TO EXPECTCLOSE
A small telescope on the line between light and dark, which is where the shadows are longest and the craters look carved rather than printed. Any evening within a night or two of this shows much the same thing.
- 24THUMOON--:--
Full moon
Up all night and fully lit — bright sky, nothing faint gets through.
+WHAT TO EXPECTCLOSE
Any eye, any binoculars, any telescope — and better through binoculars than most people expect. The one thing a full moon is bad for is the full moon itself: with the Sun straight behind us there are no shadows on the disc, so it is bright and flat. The craters look their best a week either side of tonight.
- 27SUNCONJUNCTION--:--
The Moon 1.4° from Jupiter
1.4° between the Moon and Jupiter — one binocular field, before dawn.
+WHAT TO EXPECTCLOSE
- SEPARATION
- 1.4° — about a finger-width at arm's length
- FROM THE SUN
- 129° — the angle between it and the Sun in our sky
A naked-eye sight rather than a telescope one: the two are far enough apart that magnifying them separates them. Binoculars frame the pair nicely. The nights either side are nearly as good, so cloud on the night itself is not the end of it.
- 30WEDMOON--:--
Last quarter
Half lit, rising near midnight — dark evenings, bright small hours.
+WHAT TO EXPECTCLOSE
A small telescope on the line between light and dark, which is where the shadows are longest and the craters look carved rather than printed. Any evening within a night or two of this shows much the same thing.
January 2027
] 6 EVENTS- 3SUNELONGATION--:--
Venus at its furthest from the Sun (morning sky)
Venus stands 47° away from the Sun in our sky today, the widest that gap opens on this pass. Look east shortly before sunrise: this is the easiest Venus gets to find.
+WHAT TO EXPECTCLOSE
- FROM THE SUN
- 47° — the angle between it and the Sun in our sky
Look low, into the twilight, and start before you think you need to — the planet is bright enough to find in a colouring sky and hard to find once the sky is properly dark, because by then it is setting. Binoculars help you catch it first; an unobstructed horizon in that direction matters more than any equipment.
- 7THUMOON--:--
New moon
No Moon in the night sky: the darkest week of the month.
+WHAT TO EXPECTCLOSE
There is nothing to look at, which is the point: this is the fortnight to go after galaxies, nebulae and the Milky Way, and the week either side of it is the darkest sky you will get this month. Take the faintest thing on your list.
- 15FRIMOON--:--
First quarter
Half lit and high in the evening — the best week for lunar craters.
+WHAT TO EXPECTCLOSE
A small telescope on the line between light and dark, which is where the shadows are longest and the craters look carved rather than printed. Any evening within a night or two of this shows much the same thing.
- 22FRIMOON--:--
Full moon
Up all night and fully lit — bright sky, nothing faint gets through.
+WHAT TO EXPECTCLOSE
Any eye, any binoculars, any telescope — and better through binoculars than most people expect. The one thing a full moon is bad for is the full moon itself: with the Sun straight behind us there are no shadows on the disc, so it is bright and flat. The craters look their best a week either side of tonight.
- 23SATCONJUNCTION--:--
The Moon 1.4° from Jupiter
1.4° between the Moon and Jupiter — one binocular field, before dawn.
+WHAT TO EXPECTCLOSE
- SEPARATION
- 1.4° — about a finger-width at arm's length
- FROM THE SUN
- 160° — the angle between it and the Sun in our sky
A naked-eye sight rather than a telescope one: the two are far enough apart that magnifying them separates them. Binoculars frame the pair nicely. The nights either side are nearly as good, so cloud on the night itself is not the end of it.
- 29FRIMOON--:--
Last quarter
Half lit, rising near midnight — dark evenings, bright small hours.
+WHAT TO EXPECTCLOSE
A small telescope on the line between light and dark, which is where the shadows are longest and the craters look carved rather than printed. Any evening within a night or two of this shows much the same thing.
February 2027
] 9 EVENTS- 3WEDELONGATION--:--
Mercury at its furthest from the Sun (evening sky)
18° from the Sun, west after sunset — the widest gap of this pass.
+WHAT TO EXPECTCLOSE
- FROM THE SUN
- 18° — the angle between it and the Sun in our sky
Look low, into the twilight, and start before you think you need to — the planet is bright enough to find in a colouring sky and hard to find once the sky is properly dark, because by then it is setting. Binoculars help you catch it first; an unobstructed horizon in that direction matters more than any equipment.
- 6SATMOON--:--
New moon
No Moon in the night sky: the darkest week of the month.
+WHAT TO EXPECTCLOSE
There is nothing to look at, which is the point: this is the fortnight to go after galaxies, nebulae and the Milky Way, and the week either side of it is the darkest sky you will get this month. Take the faintest thing on your list.
- 8MONCONJUNCTION--:--
The Moon 19′ from Mercury
The Moon passes 19′ from Mercury — close enough that a thumb held at arm's length covers both at once, and a pair of binoculars holds them in one field. Look after sunset; the Moon moves its own width every hour, so the gap looks noticeably different either side of tonight.
+WHAT TO EXPECTCLOSE
- SEPARATION
- 0.3° — about half a finger-width at arm's length
- FROM THE SUN
- 17° — the angle between it and the Sun in our sky
Close enough to fit in the same telescope field, which is a rarer sight than either object alone. Binoculars show it comfortably; the naked eye sees two things almost touching. Look on the evenings either side too — they will still be close, and one of the two nights is usually the clearer.
- 11THUOPPOSITION--:--
Jupiter at opposition
Jupiter is directly opposite the Sun from here, so it rises as the Sun sets, stands highest at midnight and sets at sunrise. It is also about as close to Earth as it gets this time round, which makes this its brightest and biggest night of the year — the one to point a telescope at it.
+WHAT TO EXPECTCLOSE
- FROM THE SUN
- 180° — opposite the Sun, so up all night
It rises as the Sun sets and is highest in the middle of the night, which is when to look: the higher it is, the less air is in the way and the steadier the view. Any telescope will show the disc, and a night either side of this date is indistinguishable from the date itself.
- 14SUNMOON--:--
First quarter
Half lit and high in the evening — the best week for lunar craters.
+WHAT TO EXPECTCLOSE
A small telescope on the line between light and dark, which is where the shadows are longest and the craters look carved rather than printed. Any evening within a night or two of this shows much the same thing.
- 19FRIOPPOSITION--:--
Mars at opposition
Mars is directly opposite the Sun from here, so it rises as the Sun sets, stands highest at midnight and sets at sunrise. It is also about as close to Earth as it gets this time round, which makes this its brightest and biggest night of the year — the one to point a telescope at it.
+WHAT TO EXPECTCLOSE
- FROM THE SUN
- 180° — opposite the Sun, so up all night
It rises as the Sun sets and is highest in the middle of the night, which is when to look: the higher it is, the less air is in the way and the steadier the view. Any telescope will show the disc, and a night either side of this date is indistinguishable from the date itself.
- 20SATCONJUNCTION--:--
The Moon 1.1° from Jupiter
1.1° between the Moon and Jupiter — one binocular field, after sunset.
+WHAT TO EXPECTCLOSE
- SEPARATION
- 1.1° — about a finger-width at arm's length
- FROM THE SUN
- 169° — the angle between it and the Sun in our sky
A naked-eye sight rather than a telescope one: the two are far enough apart that magnifying them separates them. Binoculars frame the pair nicely. The nights either side are nearly as good, so cloud on the night itself is not the end of it.
- 20SATMOON--:--
Full moon
Up all night and fully lit — bright sky, nothing faint gets through.
+WHAT TO EXPECTCLOSE
Any eye, any binoculars, any telescope — and better through binoculars than most people expect. The one thing a full moon is bad for is the full moon itself: with the Sun straight behind us there are no shadows on the disc, so it is bright and flat. The craters look their best a week either side of tonight.
- 28SUNMOON--:--
Last quarter
Half lit, rising near midnight — dark evenings, bright small hours.
+WHAT TO EXPECTCLOSE
A small telescope on the line between light and dark, which is where the shadows are longest and the craters look carved rather than printed. Any evening within a night or two of this shows much the same thing.
March 2027
] 7 EVENTS- 6SATCONJUNCTION--:--
The Moon 1.1° from Mercury
1.1° between the Moon and Mercury — one binocular field, before dawn.
+WHAT TO EXPECTCLOSE
- SEPARATION
- 1.1° — about a finger-width at arm's length
- FROM THE SUN
- 24° — the angle between it and the Sun in our sky
A naked-eye sight rather than a telescope one: the two are far enough apart that magnifying them separates them. Binoculars frame the pair nicely. The nights either side are nearly as good, so cloud on the night itself is not the end of it.
- 8MONMOON--:--
New moon
No Moon in the night sky: the darkest week of the month.
+WHAT TO EXPECTCLOSE
There is nothing to look at, which is the point: this is the fortnight to go after galaxies, nebulae and the Milky Way, and the week either side of it is the darkest sky you will get this month. Take the faintest thing on your list.
- 15MONMOON--:--
First quarter
Half lit and high in the evening — the best week for lunar craters.
+WHAT TO EXPECTCLOSE
A small telescope on the line between light and dark, which is where the shadows are longest and the craters look carved rather than printed. Any evening within a night or two of this shows much the same thing.
- 17WEDELONGATION--:--
Mercury at its furthest from the Sun (morning sky)
28° from the Sun, east before sunrise — the widest gap of this pass.
+WHAT TO EXPECTCLOSE
- FROM THE SUN
- 28° — the angle between it and the Sun in our sky
Look low, into the twilight, and start before you think you need to — the planet is bright enough to find in a colouring sky and hard to find once the sky is properly dark, because by then it is setting. Binoculars help you catch it first; an unobstructed horizon in that direction matters more than any equipment.
- 19FRICONJUNCTION--:--
The Moon 52′ from Jupiter
52′ between the Moon and Jupiter — one binocular field, after sunset.
+WHAT TO EXPECTCLOSE
- SEPARATION
- 0.9° — about a finger-width at arm's length
- FROM THE SUN
- 139° — the angle between it and the Sun in our sky
Close enough to fit in the same telescope field, which is a rarer sight than either object alone. Binoculars show it comfortably; the naked eye sees two things almost touching. Look on the evenings either side too — they will still be close, and one of the two nights is usually the clearer.
- 22MONMOON--:--
Full moon
Up all night and fully lit — bright sky, nothing faint gets through.
+WHAT TO EXPECTCLOSE
Any eye, any binoculars, any telescope — and better through binoculars than most people expect. The one thing a full moon is bad for is the full moon itself: with the Sun straight behind us there are no shadows on the disc, so it is bright and flat. The craters look their best a week either side of tonight.
- 30TUEMOON--:--
Last quarter
Half lit, rising near midnight — dark evenings, bright small hours.
+WHAT TO EXPECTCLOSE
A small telescope on the line between light and dark, which is where the shadows are longest and the craters look carved rather than printed. Any evening within a night or two of this shows much the same thing.
April 2027
] 5 EVENTS- 6TUEMOON--:--
New moon
No Moon in the night sky: the darkest week of the month.
+WHAT TO EXPECTCLOSE
There is nothing to look at, which is the point: this is the fortnight to go after galaxies, nebulae and the Milky Way, and the week either side of it is the darkest sky you will get this month. Take the faintest thing on your list.
- 13TUEMOON--:--
First quarter
Half lit and high in the evening — the best week for lunar craters.
+WHAT TO EXPECTCLOSE
A small telescope on the line between light and dark, which is where the shadows are longest and the craters look carved rather than printed. Any evening within a night or two of this shows much the same thing.
- 15THUCONJUNCTION--:--
The Moon 55′ from Jupiter
55′ between the Moon and Jupiter — one binocular field, after sunset.
+WHAT TO EXPECTCLOSE
- SEPARATION
- 0.9° — about a finger-width at arm's length
- FROM THE SUN
- 112° — the angle between it and the Sun in our sky
Close enough to fit in the same telescope field, which is a rarer sight than either object alone. Binoculars show it comfortably; the naked eye sees two things almost touching. Look on the evenings either side too — they will still be close, and one of the two nights is usually the clearer.
- 20TUEMOON--:--
Full moon
Up all night and fully lit — bright sky, nothing faint gets through.
+WHAT TO EXPECTCLOSE
Any eye, any binoculars, any telescope — and better through binoculars than most people expect. The one thing a full moon is bad for is the full moon itself: with the Sun straight behind us there are no shadows on the disc, so it is bright and flat. The craters look their best a week either side of tonight.
- 28WEDMOON--:--
Last quarter
Half lit, rising near midnight — dark evenings, bright small hours.
+WHAT TO EXPECTCLOSE
A small telescope on the line between light and dark, which is where the shadows are longest and the craters look carved rather than printed. Any evening within a night or two of this shows much the same thing.
May 2027
] 7 EVENTS- 6THUMOON--:--
New moon
No Moon in the night sky: the darkest week of the month.
+WHAT TO EXPECTCLOSE
There is nothing to look at, which is the point: this is the fortnight to go after galaxies, nebulae and the Milky Way, and the week either side of it is the darkest sky you will get this month. Take the faintest thing on your list.
- 7FRICONJUNCTION--:--
Venus and Saturn 36′ apart
Venus and Saturn come within 36′ of each other, close enough to look like a double star to the unaided eye and to sit in one telescope field together. They are 26° from the Sun, so look east before sunrise.
+WHAT TO EXPECTCLOSE
- SEPARATION
- 0.6° — about a finger-width at arm's length
- FROM THE SUN
- 26° — the angle between it and the Sun in our sky
Close enough to fit in the same telescope field, which is a rarer sight than either object alone. Binoculars show it comfortably; the naked eye sees two things almost touching. Look on the evenings either side too — they will still be close, and one of the two nights is usually the clearer.
- 12WEDCONJUNCTION--:--
The Moon 1.2° from Jupiter
1.2° between the Moon and Jupiter — one binocular field, after sunset.
+WHAT TO EXPECTCLOSE
- SEPARATION
- 1.2° — about a finger-width at arm's length
- FROM THE SUN
- 86° — the angle between it and the Sun in our sky
A naked-eye sight rather than a telescope one: the two are far enough apart that magnifying them separates them. Binoculars frame the pair nicely. The nights either side are nearly as good, so cloud on the night itself is not the end of it.
- 13THUMOON--:--
First quarter
Half lit and high in the evening — the best week for lunar craters.
+WHAT TO EXPECTCLOSE
A small telescope on the line between light and dark, which is where the shadows are longest and the craters look carved rather than printed. Any evening within a night or two of this shows much the same thing.
- 20THUMOON--:--
Full moon
Up all night and fully lit — bright sky, nothing faint gets through.
+WHAT TO EXPECTCLOSE
Any eye, any binoculars, any telescope — and better through binoculars than most people expect. The one thing a full moon is bad for is the full moon itself: with the Sun straight behind us there are no shadows on the disc, so it is bright and flat. The craters look their best a week either side of tonight.
- 28FRIELONGATION--:--
Mercury at its furthest from the Sun (evening sky)
23° from the Sun, west after sunset — the widest gap of this pass.
+WHAT TO EXPECTCLOSE
- FROM THE SUN
- 23° — the angle between it and the Sun in our sky
Look low, into the twilight, and start before you think you need to — the planet is bright enough to find in a colouring sky and hard to find once the sky is properly dark, because by then it is setting. Binoculars help you catch it first; an unobstructed horizon in that direction matters more than any equipment.
- 28FRIMOON--:--
Last quarter
Half lit, rising near midnight — dark evenings, bright small hours.
+WHAT TO EXPECTCLOSE
A small telescope on the line between light and dark, which is where the shadows are longest and the craters look carved rather than printed. Any evening within a night or two of this shows much the same thing.
June 2027
] 4 EVENTS- 4FRIMOON--:--
New moon
No Moon in the night sky: the darkest week of the month.
+WHAT TO EXPECTCLOSE
There is nothing to look at, which is the point: this is the fortnight to go after galaxies, nebulae and the Milky Way, and the week either side of it is the darkest sky you will get this month. Take the faintest thing on your list.
- 11FRIMOON--:--
First quarter
Half lit and high in the evening — the best week for lunar craters.
+WHAT TO EXPECTCLOSE
A small telescope on the line between light and dark, which is where the shadows are longest and the craters look carved rather than printed. Any evening within a night or two of this shows much the same thing.
- 19SATMOON--:--
Full moon
Up all night and fully lit — bright sky, nothing faint gets through.
+WHAT TO EXPECTCLOSE
Any eye, any binoculars, any telescope — and better through binoculars than most people expect. The one thing a full moon is bad for is the full moon itself: with the Sun straight behind us there are no shadows on the disc, so it is bright and flat. The craters look their best a week either side of tonight.
- 27SUNMOON--:--
Last quarter
Half lit, rising near midnight — dark evenings, bright small hours.
+WHAT TO EXPECTCLOSE
A small telescope on the line between light and dark, which is where the shadows are longest and the craters look carved rather than printed. Any evening within a night or two of this shows much the same thing.
July 2027
] 5 EVENTS- 4SUNMOON--:--
New moon
No Moon in the night sky: the darkest week of the month.
+WHAT TO EXPECTCLOSE
There is nothing to look at, which is the point: this is the fortnight to go after galaxies, nebulae and the Milky Way, and the week either side of it is the darkest sky you will get this month. Take the faintest thing on your list.
- 10SATMOON--:--
First quarter
Half lit and high in the evening — the best week for lunar craters.
+WHAT TO EXPECTCLOSE
A small telescope on the line between light and dark, which is where the shadows are longest and the craters look carved rather than printed. Any evening within a night or two of this shows much the same thing.
- 15THUELONGATION--:--
Mercury at its furthest from the Sun (morning sky)
21° from the Sun, east before sunrise — the widest gap of this pass.
+WHAT TO EXPECTCLOSE
- FROM THE SUN
- 21° — the angle between it and the Sun in our sky
Look low, into the twilight, and start before you think you need to — the planet is bright enough to find in a colouring sky and hard to find once the sky is properly dark, because by then it is setting. Binoculars help you catch it first; an unobstructed horizon in that direction matters more than any equipment.
- 18SUNMOON--:--
Full moon
Up all night and fully lit — bright sky, nothing faint gets through.
+WHAT TO EXPECTCLOSE
Any eye, any binoculars, any telescope — and better through binoculars than most people expect. The one thing a full moon is bad for is the full moon itself: with the Sun straight behind us there are no shadows on the disc, so it is bright and flat. The craters look their best a week either side of tonight.
- 26MONMOON--:--
Last quarter
Half lit, rising near midnight — dark evenings, bright small hours.
+WHAT TO EXPECTCLOSE
A small telescope on the line between light and dark, which is where the shadows are longest and the craters look carved rather than printed. Any evening within a night or two of this shows much the same thing.
August 2027
] 5 EVENTS- 2MONMOON--:--
New moon
No Moon in the night sky: the darkest week of the month.
+WHAT TO EXPECTCLOSE
There is nothing to look at, which is the point: this is the fortnight to go after galaxies, nebulae and the Milky Way, and the week either side of it is the darkest sky you will get this month. Take the faintest thing on your list.
- 9MONMOON--:--
First quarter
Half lit and high in the evening — the best week for lunar craters.
+WHAT TO EXPECTCLOSE
A small telescope on the line between light and dark, which is where the shadows are longest and the craters look carved rather than printed. Any evening within a night or two of this shows much the same thing.
- 17TUEMOON--:--
Full moon
Up all night and fully lit — bright sky, nothing faint gets through.
+WHAT TO EXPECTCLOSE
Any eye, any binoculars, any telescope — and better through binoculars than most people expect. The one thing a full moon is bad for is the full moon itself: with the Sun straight behind us there are no shadows on the disc, so it is bright and flat. The craters look their best a week either side of tonight.
- 25WEDMOON--:--
Last quarter
Half lit, rising near midnight — dark evenings, bright small hours.
+WHAT TO EXPECTCLOSE
A small telescope on the line between light and dark, which is where the shadows are longest and the craters look carved rather than printed. Any evening within a night or two of this shows much the same thing.
- 31TUEMOON--:--
New moon
No Moon in the night sky: the darkest week of the month.
+WHAT TO EXPECTCLOSE
There is nothing to look at, which is the point: this is the fortnight to go after galaxies, nebulae and the Milky Way, and the week either side of it is the darkest sky you will get this month. Take the faintest thing on your list.
September 2027
] 6 EVENTS- 7TUEMOON--:--
First quarter
Half lit and high in the evening — the best week for lunar craters.
+WHAT TO EXPECTCLOSE
A small telescope on the line between light and dark, which is where the shadows are longest and the craters look carved rather than printed. Any evening within a night or two of this shows much the same thing.
- 15WEDMOON--:--
Full moon
Up all night and fully lit — bright sky, nothing faint gets through.
+WHAT TO EXPECTCLOSE
Any eye, any binoculars, any telescope — and better through binoculars than most people expect. The one thing a full moon is bad for is the full moon itself: with the Sun straight behind us there are no shadows on the disc, so it is bright and flat. The craters look their best a week either side of tonight.
- 23THUMOON--:--
Last quarter
Half lit, rising near midnight — dark evenings, bright small hours.
+WHAT TO EXPECTCLOSE
A small telescope on the line between light and dark, which is where the shadows are longest and the craters look carved rather than printed. Any evening within a night or two of this shows much the same thing.
- 24FRIELONGATION--:--
Mercury at its furthest from the Sun (evening sky)
26° from the Sun, west after sunset — the widest gap of this pass.
+WHAT TO EXPECTCLOSE
- FROM THE SUN
- 26° — the angle between it and the Sun in our sky
Look low, into the twilight, and start before you think you need to — the planet is bright enough to find in a colouring sky and hard to find once the sky is properly dark, because by then it is setting. Binoculars help you catch it first; an unobstructed horizon in that direction matters more than any equipment.
- 28TUEOPPOSITION--:--
Neptune at opposition
Neptune is up all night, at its closest and brightest for the year.
+WHAT TO EXPECTCLOSE
- FROM THE SUN
- 180° — opposite the Sun, so up all night
It rises as the Sun sets and is highest in the middle of the night, which is when to look: the higher it is, the less air is in the way and the steadier the view. Any telescope will show the disc, and a night either side of this date is indistinguishable from the date itself.
- 30THUMOON--:--
New moon
No Moon in the night sky: the darkest week of the month.
+WHAT TO EXPECTCLOSE
There is nothing to look at, which is the point: this is the fortnight to go after galaxies, nebulae and the Milky Way, and the week either side of it is the darkest sky you will get this month. Take the faintest thing on your list.
October 2027
] 5 EVENTS- 7THUMOON--:--
First quarter
Half lit and high in the evening — the best week for lunar craters.
+WHAT TO EXPECTCLOSE
A small telescope on the line between light and dark, which is where the shadows are longest and the craters look carved rather than printed. Any evening within a night or two of this shows much the same thing.
- 15FRIMOON--:--
Full moon
Up all night and fully lit — bright sky, nothing faint gets through.
+WHAT TO EXPECTCLOSE
Any eye, any binoculars, any telescope — and better through binoculars than most people expect. The one thing a full moon is bad for is the full moon itself: with the Sun straight behind us there are no shadows on the disc, so it is bright and flat. The craters look their best a week either side of tonight.
- 18MONOPPOSITION--:--
Saturn at opposition
Saturn is up all night, at its closest and brightest for the year.
+WHAT TO EXPECTCLOSE
- FROM THE SUN
- 180° — opposite the Sun, so up all night
It rises as the Sun sets and is highest in the middle of the night, which is when to look: the higher it is, the less air is in the way and the steadier the view. Any telescope will show the disc, and a night either side of this date is indistinguishable from the date itself.
- 22FRIMOON--:--
Last quarter
Half lit, rising near midnight — dark evenings, bright small hours.
+WHAT TO EXPECTCLOSE
A small telescope on the line between light and dark, which is where the shadows are longest and the craters look carved rather than printed. Any evening within a night or two of this shows much the same thing.
- 29FRIMOON--:--
New moon
No Moon in the night sky: the darkest week of the month.
+WHAT TO EXPECTCLOSE
There is nothing to look at, which is the point: this is the fortnight to go after galaxies, nebulae and the Milky Way, and the week either side of it is the darkest sky you will get this month. Take the faintest thing on your list.
November 2027
] 8 EVENTS- 4THUELONGATION--:--
Mercury at its furthest from the Sun (morning sky)
19° from the Sun, east before sunrise — the widest gap of this pass.
+WHAT TO EXPECTCLOSE
- FROM THE SUN
- 19° — the angle between it and the Sun in our sky
Look low, into the twilight, and start before you think you need to — the planet is bright enough to find in a colouring sky and hard to find once the sky is properly dark, because by then it is setting. Binoculars help you catch it first; an unobstructed horizon in that direction matters more than any equipment.
- 6SATMOON--:--
First quarter
Half lit and high in the evening — the best week for lunar craters.
+WHAT TO EXPECTCLOSE
A small telescope on the line between light and dark, which is where the shadows are longest and the craters look carved rather than printed. Any evening within a night or two of this shows much the same thing.
- 14SUNMOON--:--
Full moon
Up all night and fully lit — bright sky, nothing faint gets through.
+WHAT TO EXPECTCLOSE
Any eye, any binoculars, any telescope — and better through binoculars than most people expect. The one thing a full moon is bad for is the full moon itself: with the Sun straight behind us there are no shadows on the disc, so it is bright and flat. The craters look their best a week either side of tonight.
- 21SUNMOON--:--
Last quarter
Half lit, rising near midnight — dark evenings, bright small hours.
+WHAT TO EXPECTCLOSE
A small telescope on the line between light and dark, which is where the shadows are longest and the craters look carved rather than printed. Any evening within a night or two of this shows much the same thing.
- 25THUCONJUNCTION--:--
Venus and Mars 19′ apart
Venus and Mars come within 19′ of each other, close enough to look like a double star to the unaided eye and to sit in one telescope field together. They are 27° from the Sun, so look west after sunset.
+WHAT TO EXPECTCLOSE
- SEPARATION
- 0.3° — about half a finger-width at arm's length
- FROM THE SUN
- 27° — the angle between it and the Sun in our sky
Close enough to fit in the same telescope field, which is a rarer sight than either object alone. Binoculars show it comfortably; the naked eye sees two things almost touching. Look on the evenings either side too — they will still be close, and one of the two nights is usually the clearer.
- 28SUNMOON--:--
New moon
No Moon in the night sky: the darkest week of the month.
+WHAT TO EXPECTCLOSE
There is nothing to look at, which is the point: this is the fortnight to go after galaxies, nebulae and the Milky Way, and the week either side of it is the darkest sky you will get this month. Take the faintest thing on your list.
- 30TUEOPPOSITION--:--
Uranus at opposition
Uranus is up all night, at its closest and brightest for the year.
+WHAT TO EXPECTCLOSE
- FROM THE SUN
- 180° — opposite the Sun, so up all night
It rises as the Sun sets and is highest in the middle of the night, which is when to look: the higher it is, the less air is in the way and the steadier the view. Any telescope will show the disc, and a night either side of this date is indistinguishable from the date itself.
- 30TUECONJUNCTION--:--
The Moon 52′ from Venus
52′ between the Moon and Venus — one binocular field, after sunset.
+WHAT TO EXPECTCLOSE
- SEPARATION
- 0.9° — about a finger-width at arm's length
- FROM THE SUN
- 28° — the angle between it and the Sun in our sky
Close enough to fit in the same telescope field, which is a rarer sight than either object alone. Binoculars show it comfortably; the naked eye sees two things almost touching. Look on the evenings either side too — they will still be close, and one of the two nights is usually the clearer.
December 2027
] 5 EVENTS- 6MONMOON--:--
First quarter
Half lit and high in the evening — the best week for lunar craters.
+WHAT TO EXPECTCLOSE
A small telescope on the line between light and dark, which is where the shadows are longest and the craters look carved rather than printed. Any evening within a night or two of this shows much the same thing.
- 13MONMOON--:--
Full moon
Up all night and fully lit — bright sky, nothing faint gets through.
+WHAT TO EXPECTCLOSE
Any eye, any binoculars, any telescope — and better through binoculars than most people expect. The one thing a full moon is bad for is the full moon itself: with the Sun straight behind us there are no shadows on the disc, so it is bright and flat. The craters look their best a week either side of tonight.
- 20MONMOON--:--
Last quarter
Half lit, rising near midnight — dark evenings, bright small hours.
+WHAT TO EXPECTCLOSE
A small telescope on the line between light and dark, which is where the shadows are longest and the craters look carved rather than printed. Any evening within a night or two of this shows much the same thing.
- 27MONMOON--:--
New moon
No Moon in the night sky: the darkest week of the month.
+WHAT TO EXPECTCLOSE
There is nothing to look at, which is the point: this is the fortnight to go after galaxies, nebulae and the Milky Way, and the week either side of it is the darkest sky you will get this month. Take the faintest thing on your list.
- 29WEDCONJUNCTION--:--
The Moon 31′ from Mars
31′ between the Moon and Mars — one binocular field, after sunset.
+WHAT TO EXPECTCLOSE
- SEPARATION
- 0.5° — about half a finger-width at arm's length
- FROM THE SUN
- 18° — the angle between it and the Sun in our sky
Close enough to fit in the same telescope field, which is a rarer sight than either object alone. Binoculars show it comfortably; the naked eye sees two things almost touching. Look on the evenings either side too — they will still be close, and one of the two nights is usually the clearer.
January 2028
] 6 EVENTS- 5WEDMOON--:--
First quarter
Half lit and high in the evening — the best week for lunar craters.
+WHAT TO EXPECTCLOSE
A small telescope on the line between light and dark, which is where the shadows are longest and the craters look carved rather than printed. Any evening within a night or two of this shows much the same thing.
- 8SATCONJUNCTION--:--
Mercury and Mars 41′ apart
Mercury and Mars come within 41′ of each other, close enough to look like a double star to the unaided eye and to sit in one telescope field together. They are 16° from the Sun, so look west after sunset.
+WHAT TO EXPECTCLOSE
- SEPARATION
- 0.7° — about a finger-width at arm's length
- FROM THE SUN
- 16° — the angle between it and the Sun in our sky
Close enough to fit in the same telescope field, which is a rarer sight than either object alone. Binoculars show it comfortably; the naked eye sees two things almost touching. Look on the evenings either side too — they will still be close, and one of the two nights is usually the clearer.
- 12WEDMOON--:--
Full moon
Up all night and fully lit — bright sky, nothing faint gets through.
+WHAT TO EXPECTCLOSE
Any eye, any binoculars, any telescope — and better through binoculars than most people expect. The one thing a full moon is bad for is the full moon itself: with the Sun straight behind us there are no shadows on the disc, so it is bright and flat. The craters look their best a week either side of tonight.
- 17MONELONGATION--:--
Mercury at its furthest from the Sun (evening sky)
19° from the Sun, west after sunset — the widest gap of this pass.
+WHAT TO EXPECTCLOSE
- FROM THE SUN
- 19° — the angle between it and the Sun in our sky
Look low, into the twilight, and start before you think you need to — the planet is bright enough to find in a colouring sky and hard to find once the sky is properly dark, because by then it is setting. Binoculars help you catch it first; an unobstructed horizon in that direction matters more than any equipment.
- 18TUEMOON--:--
Last quarter
Half lit, rising near midnight — dark evenings, bright small hours.
+WHAT TO EXPECTCLOSE
A small telescope on the line between light and dark, which is where the shadows are longest and the craters look carved rather than printed. Any evening within a night or two of this shows much the same thing.
- 26WEDMOON--:--
New moon
No Moon in the night sky: the darkest week of the month.
+WHAT TO EXPECTCLOSE
There is nothing to look at, which is the point: this is the fortnight to go after galaxies, nebulae and the Milky Way, and the week either side of it is the darkest sky you will get this month. Take the faintest thing on your list.
February 2028
] 6 EVENTS- 3THUMOON--:--
First quarter
Half lit and high in the evening — the best week for lunar craters.
+WHAT TO EXPECTCLOSE
A small telescope on the line between light and dark, which is where the shadows are longest and the craters look carved rather than printed. Any evening within a night or two of this shows much the same thing.
- 10THUMOON--:--
Full moon
Up all night and fully lit — bright sky, nothing faint gets through.
+WHAT TO EXPECTCLOSE
Any eye, any binoculars, any telescope — and better through binoculars than most people expect. The one thing a full moon is bad for is the full moon itself: with the Sun straight behind us there are no shadows on the disc, so it is bright and flat. The craters look their best a week either side of tonight.
- 17THUMOON--:--
Last quarter
Half lit, rising near midnight — dark evenings, bright small hours.
+WHAT TO EXPECTCLOSE
A small telescope on the line between light and dark, which is where the shadows are longest and the craters look carved rather than printed. Any evening within a night or two of this shows much the same thing.
- 23WEDCONJUNCTION--:--
The Moon 12′ from Mercury
12′ between the Moon and Mercury — one binocular field, before dawn.
+WHAT TO EXPECTCLOSE
- SEPARATION
- 0.2° — about half a finger-width at arm's length
- FROM THE SUN
- 26° — the angle between it and the Sun in our sky
Close enough to fit in the same telescope field, which is a rarer sight than either object alone. Binoculars show it comfortably; the naked eye sees two things almost touching. Look on the evenings either side too — they will still be close, and one of the two nights is usually the clearer.
- 25FRIMOON--:--
New moon
No Moon in the night sky: the darkest week of the month.
+WHAT TO EXPECTCLOSE
There is nothing to look at, which is the point: this is the fortnight to go after galaxies, nebulae and the Milky Way, and the week either side of it is the darkest sky you will get this month. Take the faintest thing on your list.
- 27SUNELONGATION--:--
Mercury at its furthest from the Sun (morning sky)
27° from the Sun, east before sunrise — the widest gap of this pass.
+WHAT TO EXPECTCLOSE
- FROM THE SUN
- 27° — the angle between it and the Sun in our sky
Look low, into the twilight, and start before you think you need to — the planet is bright enough to find in a colouring sky and hard to find once the sky is properly dark, because by then it is setting. Binoculars help you catch it first; an unobstructed horizon in that direction matters more than any equipment.
115 events for the 18 months from today, of the kinds selected above. Times are instants, shown on your own clock; how every number here was made.
Nothing here is a hand-kept list. Every date except the flybys is solved from the same ephemeris the rest of the site uses to place the planets, at the moment you load the page; a meteor shower is dated by the longitude the Sun reaches rather than by a day of the month, which is why its date moves a little from year to year. The same events are available as JSON and CSV.
The 38 close approaches come from NASA/JPL Center for Near-Earth Object Studies, as they stood on 2026-08-30, and cover passes inside 20 lunar distances from 2026-07-31 through 2028-04-01. Unlike everything else on this page they cannot be computed from an ephemeris here — a newly discovered asteroid has no orbit until somebody measures one — so they are as complete as that date and no more.
COMMON QUESTIONS
] 10 ANSWERED- Why is there not an eclipse every month?
- Because the Moon's orbit is tilted about five degrees to the Earth's, so at most new moons its shadow passes above or below us and misses. Eclipses arrive in seasons roughly twice a year, when the two orbital planes happen to line up with the Sun.
- What fixes the date of a meteor shower?
- Where the Earth is in its orbit, not the calendar. A shower is the Earth crossing a stream of dust a comet left behind, so the peak falls at the same point in the orbit every year and drifts by a few hours against the clock — which is why the dates here are solved rather than looked up.
- Why are moon phases on a list of events?
- Because moonlight decides what else is worth chasing. A full moon costs several magnitudes of faint detail across the whole sky, so the fortnight around new moon is when meteors, galaxies and nebulae actually repay the trip outside.
- What is an opposition, and why is it the night to look?
- Opposition is the moment an outer planet sits opposite the Sun from Earth, so it rises at sunset, stands highest at midnight and sets at sunrise. It falls close to the planet's nearest approach as well, which makes it the biggest and brightest that planet gets in the year.
- What are the equinoxes and solstices, exactly?
- The four instants at which the Sun reaches its furthest north, its furthest south, or crosses the celestial equator between the two. They are moments rather than days, and they are the same moment everywhere on Earth — which is why one of them can fall on a different date depending on your time zone.
- How close does a listed flyby come?
- Inside twenty lunar distances, which is about eight million kilometres. That is close by the standards of the Solar System and by no other standard at all: nothing on this list is a hazard, and the orbits are known accurately enough to say so well in advance.
- Do I need to say where I am?
- Not for the dates. An eclipse maximum, a shower peak or an opposition is the same instant everywhere. For whether the event clears your horizon at a sensible hour — and, for a solar eclipse, for whether you are standing inside a track a few hundred kilometres wide — the answer does depend on where you are, and the page will ask if you want it.
- How far ahead can any of this be predicted?
- Centuries, for anything driven by the positions of the Sun, Moon and planets: the ephemeris behind them holds up over far longer than a lifetime, and eclipse dates thousands of years out are routine. Meteor showers are the exception — the dates are firm and the strength is not, because it depends on how the dust happens to be distributed along the stream.
- Why do the times differ by a few minutes from other sources?
- Usually because a different thing is being timed. A shower peak is a broad maximum rather than an instant and different authorities quote it differently; a phase or an eclipse can be given in different time scales. Everything here comes from one ephemeris and is stated in one scale, so the events are at least consistent with each other.
- Can I get these into my own calendar?
- Yes. The whole window is published as a subscribable feed, so the events appear in whatever calendar application you already use and follow the solutions as they are recomputed.