Cool astronomy photos

[Witness]

IC 5070 - 20 hours on the Pelican Nebula from the backyard

All the technical details: https://www.galactic-hunter.com/post/ic ... e-backyard

[Abdul Alhazred]

Eclipse under the ISS
https://apod.nasa.gov/apod/ap200627.html



Every so often I see something the reminds me we really are living in The Future^TM after all.

[Witness]

Puppis A: An X-ray Tapestry

• Puppis A is a supernova remnant located about 7,000 light years from Earth.
• This new image includes data from Chandra and XMM-Newton and is the most complete and detailed X-ray view of Puppis A to date.
• The combined dataset reveals a delicate tapestry of X-ray light left behind by the supernova explosion.

https://chandra.harvard.edu/photo/2014/puppisa/

[Anaxagoras]

Is that blue dot in the middle a remnant or a different star in the background?

ETA:
https://en.wikipedia.org/wiki/RX_J0822%E2%88%924300

RX J0822−4300, often referred to as a "Cosmic Cannonball", is a radio-quiet neutron star currently moving away from the center of the Puppis A supernova remnant at over 3 million miles per hour (5 400 000 km/h; 1500 km/s; ~0.5% the speed of light), making it one of the fastest moving stars ever found. Astronomers used NASA's Chandra X-ray Observatory to observe the star over a period of five years to determine its speed. At this velocity the star will be ejected from the galaxy millions of years from now.

Although the cosmic cannonball is not the only hypervelocity star discovered, it is unique in the apparent origin of its speed. Others may have derived theirs from a gravitational slingshot around the Milky Way's suspected supermassive black hole, Sagittarius A*. Current theories fail to explain how such speeds can be attained from a supernova explosion. It could be a possible quark star.

However, a more recent (2012) analysis by the same group yielded a more modest recoil velocity of 672±115 km/s which is much less problematic theoretically.[3]

(No idea if this "Cosmic Cannonball" is the blue dot in the middle of that image)

[Witness]

Small observatory in Skinakas, Crete.

[robinson]

Goddamn but I love astronomy

[robinson]

I’m sitting at home looking at images and data that are simply mind blowing

I think of the old days where a lone astronomer carefully was watching through a telescope, freezing in the high altitude, with no way to even record what he saw

Other than to draw it

[Witness]

Spoiler:

Two astronomers captured the silhouette of Venus as it passed in front of the solar corona.

Sixteen years after Venus passed in front of the Sun in 2004, and eight years after its 2012 transit — rare events that won’t happen again until 2117 and 2125 — Venus again passed near the Sun on the sky. This time, while Venus did not pass directly across the Sun’s disk from our point of view, it did pass over the solar corona, coming within 13 arcminutes of the disk on June 3rd at 18:48 UT (2:48 p.m. EDT).

https://skyandtelescope.org/astronomy-n ... ona-video/

[Witness]

Ingenuity: A man's decades-long quest to fly a helicopter on Mars

NASA is about to fly a rotorcraft on another planet for the first time. And for the engineers who built the Mars Ingenuity helicopter, it's a Wright brothers moment.



When America first dreamed of sending astronauts to another world, German-American rocket engineer Wernher von Braun didn’t want to go to the Moon. He wanted to send dozens of people to Mars. He envisioned a winged craft soaring through the Red Planet’s atmosphere, landing gently on the rust-colored surface. And though earthlings quickly learned that traveling to another planet isn’t so easy, the fantasy of flying on Mars never died.

And now, that dream is on the verge of being fulfilled. On July 22, NASA plans to launch its Mars Perseverance rover. But there's also a robotic hitchhiker onboard. This small, solar-powered helicopter, named Ingenuity, is on mission totally independent from the rover. While Perseverance searches for signs of alien life, Ingenuity will prove it's possible to fly in Mars' thin atmosphere. The data it gathers will help engineers build even larger helicopter drones for the Red Planet. And if it works, the long-term impact could be a game-changer for Mars exploration.

https://astronomy.com/news/2020/07/the- ... er-on-mars

[Rob Lister]

That's one cool trick. Google tells me the density of air on Mars is 1% of what it is here. That's like flying a helo to the peak of Mount Everest. Or something. I may have just made that up out of recycled cloth.

Wouldn't a or hydrogen balloon be more technologically economical?

[sparks]

Interesting question. I suggest someone has already done the maths and it didn't work out due to the mass of the cylinder required to store the pressurized gas.

Besides, a balloon goes where the prevailing wind takes it, whereas a helicopter goes where the pilot tells it to unless the prevailing wind is lots faster than the 'copter.

[Anaxagoras]

On the other hand, the gravity is weaker on Mars.
3.711 m/s² as compared to 9.807 m/s² on Earth.
It wouldn't work on the moon, but Mars may have just enough of an atmosphere to make it possible.

[Bruce]

On the other hand, the gravity is weaker on Mars.
3.711 m/s² as compared to 9.807 m/s² on Earth.
It wouldn't work on the moon, but Mars may have just enough of an atmosphere to make it possible.

Mars is also very dry and dusty. Seems like kicking up a cloud of dust would create conditions for lightning.

[Rob Lister]

I'm sticking with the hydrogen-filled balloon. Sparks raises two issues:

1. [M]ass of the cylinder required to store the pressurized gas.
If he refers to the added mass to the rover itself, I think the science outweighs the cost. If he refers to the added mass to the cargo of the balloon, there is no reason to take the expended canister with it; just fill and release.

2. [A] balloon goes where the prevailing wind takes it.
True, but prevailing winds are a science in and of itself. You could bring more than one.

I'll go ahead and shoot a memo to Jim Bridenstine at NASA and have him work out the cost details.

@Pyrrho, I think you're off on the 4th, right? Why don't you go ahead and make up a slide deck for presentation to the NASA board on Monday. Two days should be fine, right? Nothing fancy, just fifty or slides. Use your gut for the technical stuff. Make sure you run it through HR; we don't want to inadvertently imply anything untoward therein. Best they give it a pass.

[ed]

10 Years of the Sun. We are in the future, aren't we?

[robinson]

[Witness]

Taken with a smartphone. Technical details: https://old.reddit.com/r/Astronomy/comm ... tphone_oc/.

[Witness]

Crescent nebula. Technical details: https://old.reddit.com/r/Astronomy/comm ... nt_nebula/.

[Anaxagoras]

Taken in the Adirondacks.

[robinson]