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. @unistellar.bsky.social

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

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

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.

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.

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 @adamsspaceresearch.bsky.social for the research and trajectory data. @i4interstellar.bsky.social

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.

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... @planetarysociety.bsky.social #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

Total lunar eclipse (Blood Moon) from Bangka Island, Indonesia. It was very cloudy, I almost gave up. Then in the last few minutes before the totality ended, the wind suddenly changed direction and I saw the faint sight of the moon.

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 @marcolangbroek.bsky.social‬ 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 community of amateur astronomers using @unistellar.bsky.social 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.

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.

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.

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

Happy Summer Solstice! 🌞 Compared to the year 2000, summer now arrives about 8 hours earlier—thanks to Earth’s slow axial precession. Even in just 25 years, the shift is measurable. #SummerSolstice #Astronomy

Antarctica. Good night! #SummerSolstice #astronomy

Eternal night at the South Pole sky this time of year. #astronomy

If the Moon were placed into a polar orbit, it would crash to Earth in just a few years. According to the Kozai-Lidov mechanism, the high inclination drives eccentricity so high that the Moon's perigee dips below the Earth's surface.

🌕 Tonight's full moon is the lowest in decades, but don't expect to see it unless you have a clear view of the southern horizon. In San Francisco, it maxes out at just 23° above horizon. If you're in Alaska, Iceland, or much of Scandinavia—you won’t see it at all.

Previously undiscovered #asteroid 2025 LA drops in to tell us it exists.

The #asteroid I posted about yesterday, P12aEAB, is now known as 2025 LB. On Tuesday night, it will be mag 15.9 as seen from San Francisco after sunset. I might be able to image it with my eVscope @unistellar.bsky.social. But a fast sky speed, a bright Moon or clouds might prevent this.

#asteroid P12aEAB, was discovered earlier today by Pan-STARRS1 in Hawaii and followed up by various observatories across the globe. Possibly as wide as 60 meters, it will brighten to mag 15.7 shortly after close approach of 0.4 lunar distances on June 3-4.

Newly-discovered #comet C/2025 K1 (Atlas) will be a northern hemisphere gem for much of the rest of the year, making 2 close approaches to Earth: 0.58 AU in August, and 0.40 AU in November.