Starship Asterisk*

https://www.youtube.com/watch?v=cjewFIUaBtU https://upload.wikimedia.org/wikipedia/commons/f/fe/Dwarf_Yellow-headed_gecko_edit.jpg << Autotomy (from the Greek auto-, "self-" and tome, "severing", αὐτοτομία) or self-amputation, is the behaviour whereby an animal sheds or discards...

https://www.youtube.com/watch?v=mcDcFIs8qFk Interesting fact about the Hubble: each service mission cost approximately the same as the HST itself. It was arguably a mistake to make it repairable. In the long run, it would probably have been cheaper to simply launch new ones. 1) The cost in a Hubble...

Most (maybe all?) halos are caused by either refraction or reflection from ice crystals. Neither of those phenomena, by themselves, results in color. They simply change the angle of an incoming beam of light. For refractive effects, what matters is dispersion . Dispersion is a measure of how the in...

Click on “ quadruple halo ” link for an annotates version of the image. Thanks, I didn't realize that they included an annotated version . It looks like the 22° and 46° halos are the only ones there. Why is there some distinction made for the circumscribed halo and infralateral arc? The infralatera...

Why did ancient people build pyramids? To me they resemble stratovolcanoes. Egyptians and Mayans favored a volcano-like structure perhaps because of the angle of repose but why did they think pyramids would immortalize their leaders? New tech may help uncover some answers. :thumb_up: I do know Bojo...

https://upload.wikimedia.org/wikipedia/commons/thumb/3/33/Russian_%22Vega%22_balloon_mission_to_Venus_on_display_at_the_Udvar-Hazy_museum.jpg/330px-Russian_%22Vega%22_balloon_mission_to_Venus_on_display_at_the_Udvar-Hazy_museum.jpg <<The Vega 1 Lander/Balloon capsule entered the Venus atmosphere (1...

I am thinking do they have a drought this/last year in India? Because to undertake such a project over an entire year with the same camera and location has to rely on pure luck. A full moon only lasts for some 10 to 12 hours in the night each month, and that it works out there is not any obscuring ...

Why communicate with a satellite 1 AU away when you can have a similar satellite 0.01 AU away and have ~10,000 times the signal to noise both to & from the satellite :?: That would only be the case given an omnidirectional antenna on the satellite. With a focused beam, the S/N situation is more...

Why communicate with a satellite 1 AU away when you can have a similar satellite 0.01 AU away and have ~10,000 times the signal to noise both to & from the satellite :?: Yeah, I suppose that is the ultimate problem considering the amount of data this telescope will generate. And now I think we'...

-------------------------------------------------------------------------------------- bystander 20851 / 3.94 ppd since Mon Aug 28, 2006 / Apathetic Retiree -------------------------------------------------------------------------------------- neufer 18668 / 3.77 ppd since Mon Jan 21, 2008 / Vacati...

On second thought (and to give myself a thousandth post!), a link from today's APOD (12/31/2021) has this text: L4 and L5 correspond to hilltops and L1, L2 and L3 correspond to saddles (i.e. points where the potential is curving up in one direction and down in the other). This suggests that satelli...

But Kamoʻoalewa is not at L4 or L5, right? It's distance from earth seems to vary way too much: In terms of orbit, it currently is the most stable among the quasi-satellites of Earth that have been discovered and will remain in that orbit for about the next 300 years.[7] The closest Earth approach ...

I don't understand that. Don't all the Lagrange points maintain their positions in space relative to the Earth and Sun? And another reason that L4/L5 might be bad is that those locations - and the vicinity - accumulate space debris over time and might pose a danger? Though Spitzer seemed not to hav...

https://www.youtube.com/watch?v=YtPLPdKHhe0 James Webb Sunshield Deployment Livestream! <<We're going live to cover the critical deployment of the James Webb Space Telescope's sunshield with special guest, Dr. Heidi B. Hammel! Join us to wait for the signal to come in and ask JWST Interdisciplinary...

These two wonderful image mosaics made me think about the motion of a comet nucleus and what might be happening and why. It looks to me like the nucleus is traveling in a spiral, like a thrown football,and the tail is its "wake." The caption suggests: "Likely flares on the comet's nu...

LagrangePointsSunEarth.jpg I had trouble figuring out why L2 was chosen instead of another one of the 5 Lagrange points. Clearly L3 would be terrible -- huge distance, never a clean line of communication. And L1 would not be a good choice for this mission (though it is handy for the SOHO mission). ...

Can anyone explain whether space debris accumulates at the L-points and whether it could endanger the spacecraft? I originally understood the Webb to be targeted for an L-point along the line of the Earth's orbit, and thought in terms of Jupiter's "Trojan" and "Greek" asteroids ...

(Do you think the JWST mirrors appreciated the Ariane rocket fuel shpritz :?: ) First and second stages both use oxygen and hydrogen. Doesn't seem like a problem. In any case, the mirrors are folded and protected, and I doubt that the designers overlooked the launch events. The JWST mirrors are fol...

https://www.youtube.com/watch?v=QeiQEG450gc We're not seeing a firing rocket in this image, though. We're seeing some kind of exhaust event, like a fuel dump. It may just be me but that seems like an awful waste of Ariane rocket fuel (when the JWST has so little to spare). Other than the fact that ...

I, for one, never thought the shot was faked, only that it needed further explanation of it's unusual appearance. Unusual to me anyway - my posting history will show that I find a lot of stuff unusual looking :) Until someone addresses my concern about an Ariane rocket that stopped firing over East...

Until someone addresses my concern about an Ariane rocket that stopped firing over East Africa at an altitude of 1,000 km being clearly visible in the skies over Thailand I remain a skeptic. :? We're not seeing a firing rocket in this image, though. We're seeing some kind of exhaust event, like a f...

From what distance is this photo taken? https://photojournal.jpl.nasa.gov/catalog/PIA25031 <<Original Caption Released with Image: This image shows two of Jupiter's large rotating storms, captured by Juno's visible-light imager, JunoCam, on Juno's 38th perijove pass, on Nov. 29, 2021. This image wa...

------------------------------------------------------------------------------------------- The Aft Unitized Pallet Structure (UPS) Nominal Event Time: Launch + 3 days <<The UPS supports and carries the five folded sunshield membranes. Prior to this, the spacecraft will have been maneuvered to prov...