The Astronomy Thread

MusicForFish said:

This terrible article/theory is similar to the article I read a few months ago. Trying to find the link still. Should have bookmarked it. It's similar to the Nemisis theory in some regards.

Sun has binary partner, may affect the Earth

The ground-breaking and richly illustrated new book, Lost Star of Myth and Time, marries modern astronomical theory with ancient star lore to make a compelling case for the profound influence on our planet of a companion star to the sun. Author and theorist, Walter Cruttenden, presents the...

phys.org

Edit* It's an "updated with new study info" version of this one, but on a more professional site with citations.

New evidence that all stars are born in pairs

Did our sun have a twin when it was born 4.5 billion years ago?

phys.org

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Considering that there are actual observations of star systems forming that do not involve pairs of stars at various points in the process, this is obviously bunk.

The Nemesis (companion star) hypothes is pretty much dead because it would have been detected in IR surveys by now. A cold and distant planet is still possible and has been suggested as an answer to observed clustering of Kuiper belt objects. Scott Manley did a video on it a few years ago, I think this is it.

meStevo said:

This rover and it's helicopter launch tomorrow morning at 4:50am PST.

Launch - NASA

The Mars 2020 spacecraft with its Perseverance Rover will launch on an Atlas V-541 rocket from Launch Complex 41 at Cape Canaveral Air Force Station, Florida.

mars.nasa.gov

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That just seems like a bad idea, for longevity at least. Moving parts at that speed might decay super fast?

It's a good proof of concept. Even if it fails or doesn't last long, what they will learn from it will help them develop improvements. The air on Mars is so damn thin, your options are limited for maneuverable craft. Helicopter blade-style drones have been tested a lot on Earth already and they're good for autonomous/minimal human involvement because worst case scenario, they can hover in place or quickly land if something goes wrong. An inflatable craft wouldn't be able to do that as well, nor would some traditional aircraft-style drone.

Ya, if you look at the specs for it, it's fairly barebones. It's only designed to fly for around 90 seconds per day. Mars team basically plots a flight path, the thing runs it on its own, then they can examine the results later.

But if this is successful or they learn a lot from it, future Mars missions could be much more ambitious. In theory you could fly these things into caves to explore, or past obstacles that would give rovers trouble. And if you put humans on Mars, having scouting drones like these would be very useful.

Successful launch this morning:

2021 should be a good year for Mars stuff. In addition to Perseverence, a Chinese mission launched last week which includes a lander and rover too. Emirates launched their first mission as well although that is an orbiter only.

I think only the US has successfully landed on Mars thus far? Failure rate for Mars missions is fairly high across all missions over all, esp non-US

Lambourne said:

The Nemesis (companion star) hypothes is pretty much dead because it would have been detected in IR surveys by now. A cold and distant planet is still possible and has been suggested as an answer to observed clustering of Kuiper belt objects. Scott Manley did a video on it a few years ago, I think this is it.

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Maybe the Elusive Planet 9 Doesn't Exist After All - Universe Today

Basically claims that observational biases about when and how we find KBO's made it seem like there was a clumping together of objects that a potential Planet 9 could explain, but in fact there isn't actually a clumping going on.

Tracking map for Perseverance.

Cool thing is you can go to Solar System view and alter axis and zoom out to see Voyager and other probes location.

Any reason the Dragon is splashing down for the first time since 75? Hell, I was only a few years old the last time it happened.

Big Phoenix said:

You mean why its landing in water v on land?

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Ya. I know we didn't send people up for a long time with the shuttle program. Obvious why it didn't land on water but the past years it was just never done. Wondering why now.