☄️ 3I/ATLAS... ...FAST APPROACHING🔴 #MARS!!! Close encounter is THIS Friday & as an astronomer (former #NASA) & planetary scientist it made me wonder: ✨WHAT CAN WE EXPECT??? BUCKLE UP & Let's Take A HARD LOOK! 💥Turns out this is NOT the only time #NASA has mobilized spacecraft to look at a #comet As a matter of fact the upcoming encounter is pure DEJA VU! 💥A look back will SURPRISE you: FLASHBACK 11 years ago... - it's 2014 & #Comet C/2013 A1 #SidingSpring has plunged in from almost outside our Solar System, from the distant Oort Cloud & is fast approaching #Mars... SOUNDS ALMOST FAMILIAR! Just like now, back then multiple spacecraft🛰️ WERE ALL mobilized to observe this ☄️comet, including: -Mars Reconnaissance Orbiter -2001 Mars Odyssey -ESA's Mars Express -MAVEN -Indian Mars Orbiter Mangalyaan ~ & on Mars SURFACE: BOTH #Curiosity & #Opportunity rovers! ⚡The comet flew by #Mars SOOOOO CLOSE (only ~138,000 km!) that orbiters were repositioned in order to protect them from possible damage from cometary particulates. Even at such close range, although good science was obtained - from a strictly public perspective, the IMAGES were NOT spectacular - see below👇 💥In comparison 3I/ATLAS, at ~17 M-miles, will be ~195 TIMES FARTHER from Mars! Let me repeat & rephrase that: #CometSidingSpring flew by #MARS 195 TIMES CLOSER than #3IATLAS will! 💥Although 3I/ATLAS is a fascinating object worth studying - contrary to what SOME people are claiming - such close encounters are obviously NOT that anomolous... ✨🌠 So using data from 2014 #CometSidingSpring encounter... I ran the numbers & got: 💥 In #MRO images everyone is looking forward to so much: 3I/ATLAS will probably appear as only a: FUZZY DOT or smudge - an unresolved point source or a minor variation in brightness/color within ONE PIXEL that is blended with the surrounding space background. NO shape NO surface features NO texture NO internal structure ...will be discernible, since 3I/ATLAS is WAY SMALLER than the resolution limit & 195 TIMES FARTHER than #Comet #SidingSpring was. ✨IF #3IATLAS brightens considerably & grows a big tail: larger extended features might span ONLY several pixels ✨IF the coma somehow manages to exceed ~50-100 km in diameter, this MIGHT allow some BLURRY structure in the gaseous envelope to be visible 💥My calculations align with #HiRISE's performance in past comet imagings, including Comet Siding Spring in 2014 where at MUCH CLOSER distance (138,000 km) yielded ONLY ~138 m/pixel resolution, & so resolved a ~0.5-1 km nucleus across only 3-7 pixels & showed ONLY basic shape. 💥 WHAT ABOUT THE SURFACE ROVERS??? Surface rover imaging didn't do much better either👇 So it seems those hyping this encounter will have to temper their expectations, given that 3I/ATLAS nucleus is barely 5 km width, & is ~195 TIMES FARTHER AWAY (at ~27 MILLION KM), probably NO real details of the 3I/ATLAS itself will be seen - only perhaps its overall presence as a FUZZY POINT-LIKE FEATURE - & that's it (sorry!) 💥💥💥💥💥💥💥 I HONESTLY HOPE I'M WRONG & #3IATLAS puts on an unexpectedly spectacular show! Also, one can hope that some advanced AI image processing MIGHT produce at least some improvement BUT I doubt it... TAKE A GOOD HARD LOOK AT WHAT HiRES produced 11 yrs ago on #Comet #SidingSpring 👇 AND REMEMBER to keep in mind that #Comet #SidingSpring was 195 TIMES CLOSER.than 3IATLAS... ICYMI: ✨ x.com/MarianRudnyk/status/19… ✨ x.com/MarianRudnyk/status/19… #astronomy #ufoX #uap @CNN #AviLoeb @PhDBrandenburg @rosscoulthart @GeologicalSETI @g_knapp @FoxNews @ABC

487P/SidingSpring Dec. 01.47, 15.0, 0'.4 (0.20-m f/8 Ritchey-Chretien CMOS f/5.4 focal Reducer; tail 1'.2 in p.a. 190 deg); #Cometobs

Yesterday was 10 years since the Sun ejected one of the most spectacular CMEs. We tracked it at Venus, Mars, comets 67P and SidingSpring, Saturn, Pluto & even @NASAVoyager, with @esascience and @NASASolarSystem. A great and funny study led by @OWitasse sci.esa.int/web/solar-system…

Happy 50th birthday @SidingSpring 🎂#starfest

P/2012 US27 = 2024 N5 (SidingSpring) Sept. 13.77, 17.2, 0'.2 (0.20-m f/8 Ritchey-Chretien CMOS f/5.4 focal Reducer); #Cometobs

The beginning of another night at the #AAT @SidingSpring ✨

🇪🇸🇦🇺 fusion breakfast with views at @SidingSpring. I’ve been observing with KOALA AAOmega at the Anglo-Australian Telescope, tonight is my 3rd & last night. Great weather, data & environment, this is such an awesome place with amazing people providing their best for #science!

Thanks to @TimElliottSMH for his interest in this topic. Light pollution is the least known but easiest solved pollutant. Articles like this go a long way to raise awareness @IDADarkSky @SidingSpring @ANUmedia

Afternoon walk around @SidingSpring, enjoying the sunshine, clear skies and fresh air… 3rd night to go, too many hours (the longest nights of the year, as very close to Winter solstice) in front of screens… but outstanding dark sky at night!

Good luck to our @CGA_ANU @ARC_OzGRav scientists in their new quest to find violent collisions ever deeper in the universe @LIGO #O4IsHere. Great to have @StromloANU new robotic telescope @SidingSpring following up too physics.anu.edu.au/news_even…

The new #LIGO remote control room @PhysicsANU and additional Electromagnetic follow-up capabilities @SidingSpring puts @ourANU in the centre of the global #O4IsHere observing run. youtu.be/Ki1ZDY86qEE @ausphysics @ARC_OzGRav

Both systems are now on sky and taking data at GOTO South @SidingSpring - commissioning continues at pace, as we optimise 16 new unit telescopes for maximal performance, and tie them into our control/scheduling software. Stay tuned for our first light image from the South!

Physics-based AI enables Digital Twin of the Orbital Environment to predict visual magnitude of Starlink satellites: youtu.be/7sgRfMlIkNM @IDADarkSky @NSF @NatGeo @SidingSpring @IIABengaluru @VRubinObs @TMTHawaii @darkskyalliance @SpaceX @NASA @AerospaceCorp @SpaceForceDoD

This is awful - and completely unnecessary. Makes my heart sink in despair. Where is it? In a paper I wrote 5 years ago, I advised NSW Environment planning of sunroof companies that technology that would block out light waste like this THEN. @NSWDPE @SidingSpring

An amazing legacy and shows the patience and collaborative approach by Reg. So will miss his voice.

@JohnBarentine @WarrumbungleSC @SidingSpring

After 4 days of hard work, ably supported by the ANU site staff, we now have two fully functional domes! Next step will be the telescope deployment, hopefully to take place in early 2023 (in time for @LIGO's 4th observing period)

After some long delays including from serious flooding in parts of NSW, the platform for our GOTO-South node at @SidingSpring was finally completed in late November. This week collaboration members Paul Chote and @DuncanKGalloway visited to assemble the domes

Starlink constellation is growing fast youtu.be/bA6V8BL-8EI Astrodynamics tools help to mitigate against the light pollution that affects astronomical fundamental research @SpaceX @IDADarkSky @NSF @NatGeo @SidingSpring @IIABengaluru @VRubinObs @TMTHawaii @darkskyalliance

All hands on deck at Siding Spring Observatory (@SidingSpring) to get the groundwork done for GOTO-South - even the local wildlife is pitching in!