#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.

#GoldenGateBridge #SanFrancisco Dec 2, 2022

In the next few hours, asteroid 2025 KE1 will pass closer than the Moon. If you're in India, the Middle East, or Africa, it could reach mag 13.2—bright enough for astrophotographers to catch.

Dwarf Planet candidate 2017 OF201 cruising through the sky from its earliest precovery images to today. Accurate GAIA stars included. Uncompressed version: orbitsimulator.com/BA/2017_OF20...

🚨 New dwarf planet candidate: 2017 OF201 🚨 ~700 km wide, now 90.5 AU from the Sun. Orbit: a = 838 AU, q = 44.9 AU — deep into the inner Oort Cloud. Possibly part of a hidden population totaling ~1% of Earth’s mass. 📄 Paper: arxiv.org/pdf/2505.15806 #astronomy #dwarfplanet

Asteroid 1999 HF1 was 1/2 AU above Earth last night. This asteroid, possibly 7 km wide, was mag 15.8 when I caught it with my @Unistellar eVscope from my San Francisco backyard.

#asteroid #Apophis, at naked-eye brightness (mag 3.1) races across Barcelona's night sky on the evening of Friday, April 13, 2029 as it comes closer to Earth than our geosynchronous satellites.

A visual look at two possible orbits for Planet Nine—one based on @plutokiller & @kb4batygin’s model, the other inspired by a recent IRAS/AKARI paper (arXiv:2504.17288) by @takao_nakagawa, @AmosChen, @frosztfang, @NomisOh, and @seongjin_torres.

1 year ago today.

#Asteroid 2024_YR4 may collide with the Moon 🌙 Its nominal trajectory, based on updated observations, shows a lunar impact on Dec 22, 2032. But the odds of collision remain low.

#Asteroid 2024_YR4 may collide with the Moon 🌙 Its nominal trajectory, based on updated observations, shows a lunar impact on Dec 22, 2032. But the odds of collision remain low.

🚀 All of the hyperbolic spacecraft currently escaping the solar system. Explore them in this interactive, pan-able browser simulation: orbitsimulator.com/gravitySimul...

In the last 3 days, 6 newly-discovered #asteroids passed closer than the Moon: 2025 FY6, 2025 FK3, 2025 FX6, 2025 FC2, 2025 FX2, 2025 FZ6.

#Asteroid 2025 FC tried hard to avoid detection. The 3-10 meter rock approached Earth from the daytime sky. Shortly after close approach of 60,000 km over the South Pacific Ocean, it briefly hid in the Earth's shadow before being detected.

#Asteroid 2025 EF4 is visible all night. At mag 14, it will be an easy target for astrophotographers. @unistellar.bsky.social

Asteroid 2025 EF4 was discovered just three days ago. Tonight, it will brighten to magnitude 14—perfect for astrophotography! It will pass just 1.2 lunar distances from Earth and may be up to 65 meters wide. If the weather cooperates, I'll try to capture it with my eVscope. @Unistellar

Tonight's eclipse as viewed from the Moon.

Here is a link to a higher-res version: orbitsimulator.com/misc/Saturns...

Saturn has 128 newly-discovered moons. Here they are color-coded by their MPEC release. Orange: MPEC 2025 E153, Purple: MPEC 2025-E154, Green: MPEC 2025-E155.

#Asteroid 2018 RC2 is currently making a very bright apparition (mag 13.7) in North American skies. This is bright enough to pick up on a Unistellar eVscope or other astrophotography gear.