Why is tonight's Full Moon so low? For the Northern Hemisphere, around the June Solstice, the full Moon takes its lowest path of the year. We're also near a minor lunar standstill, making the Moon's nightly path even lower than usual. 🔭 #astro

Venus-Jupiter conjunction simulated. Planets' diameters exaggerated 100x. 🔭 #astro

For a couple weeks around the 𝐉𝐮𝐧𝐞 𝐒𝐨𝐥𝐬𝐭𝐢𝐜𝐞, there is a brief moment each day when 𝟏𝟎𝟎% of mainland North America is on Earth's day side while 𝟏𝟎𝟎% of mainland South America is on Earth's night side, defined by 𝐭𝐡𝐞 𝐭𝐞𝐫𝐦𝐢𝐧𝐚𝐭𝐨𝐫. 🔭 #astro

A proposed mission to Kuiper Belt object 2002 XV₉₃ • Launch: 2034 • Jupiter gravity assist • Uranus plane-change maneuver • Flyby in 2043 Trajectory found by . www.youtube.com/watch?v=FHV4... 2002 XV₉₃ is in the news because it may possess a thin atmosphere.

Tomorrow, asteroid 2026 JH2 will pass less than 1/4 the distance of the Moon as it flies over South Africa. #astro 🔭

This asteroid, previously known as ST26E86 is now known as 2026 JN4 🔭 #astro

Earlier today, an asteroid about the size of a person impacted Earth over Papua New Guinea. This is only the 12th object to be discovered before impact. #astro 🔭

Inspired by the 12,000 Artemis II images just released, a simulation of Earthset as seen by the astronauts (3:16 real time). A bit slower than a sunset on Earth. 🔭 #astro Timelapse (15 seconds): orbitsimulator.com/BA/artemis_I... Real speed (3:16): orbitsimulator.com/BA/artemis_I...

A rocket booster will slam into the Moon on August 5. 2025-010D is the upper stage of a Falcon 9 rocket that brought the Blue Ghost Mission 1 to the Moon.

Newly-discovered asteroid 2026 HZ4 approached closer than our geostationary satellites 2 days ago. It is 2-7 meters wide. 🔭

The Moon.Simulation.

Artemis II splashdown off San Diego, less than 45 minutes from now. Inertial frame.

Artemis II doesn’t reverse direction like its ground track implies. Far out, its motion is mostly radial (toward Earth), so its small eastward speed is slower than Earth’s rotation, so it appears to drift west. Closer in, tangential speed grows and overtakes Earth’s rotation, so it moves east.

In a few hours, at ~9 PM PDT, Artemis II will be halfway between Earth and the Moon (by distance). The Moon will look unusually large to the crew. But they’re not halfway there in time. Earth’s gravity has been slowing them the entire way, and will continue to do so.

Right now, the astronauts must be thinking: "The Earth is getting awfully big in the window." Artemis II is dropping toward perigee for the TLI burn that will send it to the Moon.🔭 #astro

Here's a view of what the astronauts on Artemis II see right now. This is very similar to what their view will be in 24 hours when they will perform the TLI burn that will send them to the Moon.

A view of Earth from Artemis II. If you can see your region, then you might be able to spot Artemis II with a telescope or binoculars. #astro 🔭

I forgot to put the 🔭emoji in my post, so it didn't show up on the Astronomy feed!

Artemis II is scheduled to launch on Wednesday evening.

Asteroid 2024 YR₄ will NOT hit the Moon. JWST observations refined the orbit, dropping the lunar impact probability from 4% to zero. Independent researcher Sam Deen had already reached the same conclusion using 2016 precoveries. science.nasa.gov/blogs/planet...

Totality. Lunar eclipse.

The Lunar eclipse, which just began, would be a solar eclipse if you were on the Moon. Here's a view from the Moon.

Asteroid 2025 MH348, discovered last year, is possibly a trojan of Neptune. #astro 🔭

For those commenting that Voyager 1 will be 1 light day away in November 2026, that's from Earth. My post said from the Sun. That happens on February 3, 2027.

In 1 year from today, Voyager 1 will be one light day from the Sun. 🔭 orbitsimulator.com/gravitySimul...

116 years of Barnard's Star: 1940 to 2056. Proper motion and parallax are visible. The field of view is ~ as wide as the full Moon. #astronomy #astro 🔭

What would happen if you took a full-sky picture every day at noon from San Francisco for a year? I have no idea! It’s too cloudy here. So I simulated it. #astronomy #analemma

Space ambulance: Dragon returns a sick astronaut to Earth. Shot from San Francisco minutes before splashdown off San Diego. Skip to ~1:00 if the slow horizon motion bores you. Thank you for reminding me to look up! pic.x.com/cuXLHH2N2h

Comet 3I/ATLAS, our interstellar visitor, poses for my eVscope from San Francisco.

The first 4 asteroids discovered this year are 2026 AA 2026 AB 2026 AC 2026 AD

Finally! Tens of thousands of asteroids are found each year. Yet 2026 had ZERO through Jan 6. The drought is over. Possibly as big as a jet liner. Possibly as large as a football field. Meet 2026 AA. Blame the Full Moon for the drought.🌕 Expect many more soon.

Polaris is not always the North Star. Due to Earth's precession, over the course of 26,000 years, Polaris, Alderamin, Vega, and Thuban take turns as the closest prominent star to the celestial pole.

Flying into Orion’s Belt at 0.001c 🌌 The hunter isn’t flat. It’s a real 3D region of space. (Upgraded animation!) #astronomy 🔭

A little clarification. the 0.001c is with respect to the proper motion of the stars, which do have 3d velocities in the simulation. Then the video is sped up to take ~23 seconds.

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Taurus is prominent in January's evening sky. The Hyades star cluster forms its familiar V-shape, and Aldebaran appears to belong to the cluster. But over ~100,000 years of proper motion, the illusion breaks: Aldebaran is moving to its own beat.

18 asteroids passed closer than the Moon in November. And every one of them was discovered this month. #Astronomy

Newly-discovered asteroid 2025 WZ₃ is currently passing through Earth's anti umbra 3 days before making a close approach of 1.15x the Moon's distance.

Just to clear up a little confusion. That little black dot on the Sun today is the Earth, not the asteroid. This is a view from the asteroid. Enlarge the image and look closely. You will see Eurasia.

Asteroid 2022 RD₂ may become a mini-moon not once, but three times in 2043–2044. This may not exactly look like an orbit, But during each capture, if the Sun suddenly vanished, RD₂ would remain gravitationally bound to Earth indefinitely. iopscience.iop.org/article/10.3...

After these mini-moon events, it will enter a horseshoe orbit. It has a 1 in 1000 chance of impacting Earth in the next hundred years. But don't worry, it's too small to cause damage.

In an edge-on view from the ecliptic, 2022 RD₂'s vertical motion is prominent.

Comet C/2025 D1 (Groeller) has a perihelion over 14 AU, making it too dim for my backyard telescope. But it looks nice in Orbit Simulator. #Astronomy

The ESCAPADE mission to Mars is about to launch. It will stay near Earth for about 1 year before using an Oberth maneuver to send it to Mars.

Potentially Hazardous #Asteroid (PHA) 3361 Orpheus is an Apollo-class Near-Earth Asteroid (NEA). Last night it posed for a 30-minute image taken with my eVscope from San Francisco. Dim, mag 15.9 it is centered in the image.

The asteroid is now known as 2025 UC11. This animation shows where the observations were made. #astronomy

With the updated name comes an updated distance. Now ~230 km above the surface. Still in the thermosphere.

A quick trip through the thermosphere turns newly-discovered asteroid ST25J47 from an Apollo to an Aten. It is no bigger than a meter.

After billions of years heading towards us, interstellar comet #3IATLAS is currently at its closest approach to the Sun right NOW. Perihelion. #astronomy #comet

Another mini-moon? Maybe. Newly discovered 2025 US6 is officially listed as an asteroid. Unlike our quasi-moon 2025 PN7, this one is actually bound to Earth, for now. Its orbit is pure chaos. Enjoy it while it lasts. It’ll probably be demoted to space junk.

This chaotic path is just one of many possible solutions. With only a few hours of data, small uncertainties blow up fast, especially with close Moon encounters.

Some YouTubes, even one by a famous astrophysicist, confuse mini-moons with quasi-moons. Simple test: 🔴 Delete the Sun. – Still orbiting Earth, even years later? Mini-moon (bound), like 2024 PT5. – Gone forever? Quasi-moon, like 2025 PN7.

What was 'quasi-moon' 2025 PN7 doing before it entered its quasi state? It was tracing horseshoe orbits. Horseshoe orbits are called that because some people think they look like horseshoes.

Watch Earth’s newest quasi-moon in motion. 🌍🌀 The new paper “Meet Arjuna 2025 PN7” confirms #asteroid 2025 PN7 is trapped in a quasi-satellite orbit, looping around Earth (in a rotating frame) from the 1960s to the 2080s. iopscience.iop.org/article/10.3...

Two Near-Earth Asteroids (NEAs) in the same field of view in my eVscope @unistellar. 2004 FN18 (middle) and 2000 EZ148.

2 Near EarthAsteroids in 1 FOV? Last night I imaged 2000 EZ148 at mag 15.1, and 2004 FN18 at mag 15.6 from San Francisco with my eVscope. Tomorrow night (Friday around 11pm PDT), they will be of similar brightness as they pass only 0.33 degrees from each other. 2000 EZ148 is the left image.

Simulation of the 2 asteroids against GAIA stars.

What if Juno left Jupiter to get a closer look at interstellar comet 3I/ATLAS? With a couple of burns, Juno can get as close as 25 million km. Purely hypothetical, fun orbital mechanics! 🔭 Thanks for the research and trajectory data.

After last week's asteroid buzzed over Antarctica, the North Pole gets its turn. Newly-discovered #asteroid 2025 TQ2 (2-4 meters wide) passed 3,000 miles above the Fortress of Solitude. #Astronomy

Interstellar #comet 3I/ATLAS is hidden on the far side of the Sun from Earth. But today it sweeps past Mars, where orbiting spacecraft have ringside seats. Let’s hope they look up. #astronomy #NASA

An #asteroid passed just 300 km above Antarctica earlier today. It was not discovered until hours after close approach.

If you were in Antarctica, here's the #asteroid's path across the twilight sky.

10 #asteroids passed closer than the Moon in a 5-day period from September 23-28. All were discovered this month. The largest up to 41 meters wide. #astronomy

October's comets. SWAN C/2025 R2, and Lemmon (C/2025 A6). Our interstellar visitor 3I/Atlas aka C/2025 N1, is unfortunately on the wrong side of the Sun for viewing, but I included it anyway because... well... it's interstellar. #Astronomy

#Asteroid 2024 YR4 has a ~4 % chance of hitting the Moon on Dec 22 2032. A strike could spike micrometeoroid flux in low Earth orbit ~1000×, endangering satellites—so researchers even study nuclear disruption. arxiv.org/pdf/2509.12351 My sim: 2000 clones; 72 hit.

Yesterday, newly-discovered #asteroid 2025 SU4 🦒passed closer than our geostationary satellites.

#SanFrancisco Earthquake just now. Shaking started before the cell phone alert sounded.

In the last 6 days, 9 asteroids passed inside the Moon’s orbit. Estimated sizes: ~1–38 m. All were discovered this month, a reminder that countless small, faint NEOs slip by unnoticed until they make a close pass.

It might seem scary that two mega-Chelyabinsks passed closer than the Moon this week. Good news: Earth is a small target. Even with gravitational lensing, our planet is only about 80% the size of a dartboard’s bullseye compared to the board itself. In fact, 2013 was the last time I had a bullseye.

El recientemente descubierto #asteroide #2025RJ2 pasará a solo 13.000 km de la #Luna. Cada vez el rastreo con los programas de seguimiento digitales son más efectivos. Vivimos una auténtica revolución como explico en: theconversation.com/la-revolucio... #PlanetSci 👇

Tomorrow, newly-discovered #asteroid 2025 RJ2 will miss the Moon by 13,000 km. Shortly before close approach, it will pass through the Moon's shadow.

A simulation of Earth's present and former quasi satellites as described in the Carlos de la Fuente Marcos and Raúl de la Fuente Marcos paper iopscience.iop.org/article/10.3... including newly-discovered 2025 PN7, first recognized as quasi by @AdrienCoffinet

A quasi-satellite isn’t a moon. It shares Earth’s year and, in Earth’s rotating frame, loops around Earth while staying Sun-bound.

Tomorrow is a #LunarEclipse2025 . 6 months ago I was clouded out. This time I'm in the wrong hemisphere Good luck to the Eastern Hemisphere.

#Asteroid (669952) Kootker, named after @LisetteKootker, was discovered by ‬ and @sarneczky. Most named asteroids are common main-belters. Not Kootker. It is in an 8:11 librating resonance with Mars. So in a rotating frame, it traces a striking path. #astronomy

In the past 3 days, two asteroids — 2025 PF2 and 2025 PU1 — passed closer than the geostationary satellites delivering our preseason #NFL games this weekend. #asteroid #astronomy

A spacecraft that loops endlessly between Earth & Moon without extra fuel? See this 1:1 Earth–Moon cycler from @RossDynamicsLab’s “Stable, Low-Energy Prograde Earth–Moon Cycler Orbits” 📄 ross.aoe.vt.edu/papers/ross-... 🖥️ Simulation: orbitsimulator.com/gravitySimul... #astronomy

There is a big difference between the two

#SanFrancisco, a 1-foot tsunami is not the same as a 1 foot tide. It is a wall of water in motion. It's the energy, not the height, that's dangerous. Don't go to the beach to watch this. #tsunami #LosAngeles #SanDiego, #Seattle

Trans Neptunian object 2020 VN40 is in a 10:1 resonance with Neptune. Here is an animation holding Neptune stationary so you can see this resonance. iopscience.iop.org/article/10.3...

A still screen shot from the animation.

A community of amateur astronomers using smart telescopes have been observing comet C/2025 N1 (ATLAS) – also designated 3I/ATLAS – and have managed to captured images of the interstellar comet. www.skyatnightmagazine.com/news/unistel...

July 10's Full Moon, competes with June's full Moon for lowest full Moon in years. Many northern hemisphere locations will not see it at all. Here's the waxing gibbous from #SanFrancisco today.

Interstellar visitor confirmed. #A11pl3Z is now known as 3I/ATLAS. It is only the third confirmed object from beyond our solar system.

Here is a still shot of 3I/ATLAS

3rd interstellar object discovered? Maybe. There's a lot of buzz right now in the Astro community. More observations should come in tonight to confirm if A11pI3Z is from beyond the solar system.

New observations came in over night. Here's A11pl3Z's updated path. It now passes inside Mars' orbit. In yesterday's animation, the camera was below the ecliptic. This is from above, so if it looks mirrored, that's why. #astronomy #A11pl3Z

And a still shot of #A11pl3Z

Georgia bolide: A fiery visitor streaked through the sky today, dropping meteorites across the Peach State. The devil might’ve gone down to Georgia, but this one came in fast from above. This animation is an educated guess at its path. #Atlanta #Georgia #Astronomy #Meteor

If you want to see the 8 new #NEA asteroids discovered by the Vera C. Rubin Observatory tonight, northern hemisphere observers need to look to the southwestern sky. Not surprising, because #RubinObservatory is in Chile. They're also mag 24-25 so you'll need a huge telescope too.

But to the Rubin observatory, they'll be high in the sky.

8 new Near-Earth Asteroids have been discovered by the Vera Rubin Observatory from just 10 hours of sky scanning over the course of a few nights. Imagine what Rubin will do when it's fully operational. #LSST #RubinObservatory #NEO

Mazatlán, April 2024