Space In General

[CodeRedR51]

Falcon Heavy launch coming up on Sunday, window opens at 6:36pm EDT. There won't be a huge wait after this one for the 3rd, this exact same booster configuration will be refurbished and re-used for a US Air Force satellite launch in June. (current target)

 

[prousonhairy]

I read this earlier, thought it was an April fools joke, until I seen it on several other websites. This will be cool me thinks:

https://www.popularmechanics.com/sp...-to-see-the-first-ever-photo-of-a-black-hole/

 

[Novalee]

I found this to be interesting





The idea that earth was transformed into hot gas after the collision is mind bending

 

[Novalee]

Young Astronomer Uses Artificial Intelligence To Discover 2 Exoplanets


Astronomers already knew of about 4,000 exoplanets, so finding two more might not seem like huge news. But it's who found them and how that's getting attention.

Anne Dattilo, a senior at the University of Texas, Austin, found the planets by using an artificial intelligence program to sift through a mountain of data collected by NASA's Kepler space telescope. By using AI, the 22-year-old is helping to usher in a new era in astronomical research.

https://www.npr.org/2019/04/01/7079...ificial-intelligence-to-discover-2-exoplanets


Kinda cool i think

 

[Dotini]

India on Wednesday destroyed a low-orbiting satellite in a missile test that puts the country in the space "super league", Prime Minister Narendra Modi said.


India seems to be making moves in space missle defence .

https://www.aljazeera.com/news/2019...-space-super-league-modi-190327071419578.html

NASA is very unhappy with India!


from Spaceweather.com:

SOLAR MINIMUM IS A TERRIBLE TIME TO BLOW UP A SATELLITE: Note to space powers: If you're going to blow a satellite to bits, solar minimum is a terrible time to do it. India is grappling with this important truth today as debris from their March 27th anti-satellite weapons test spreads through space. As many as 6,500 pieces of the Microsat-R Earth observation satellite are now circling Earth, according to a simulation created by Analytical Graphics Inc.:


During solar minimum--happening now!--Earth's upper atmosphere cools and contracts, sharply reducing aerodynamic drag that causes satellites to decay. Indeed, in 2019 the temperature of the thermosphere is close to a Space Age record low. This could double or triple the time required for fragments of the shattered satellite to sink into the atmosphere and disintegrate. Small fragments in high orbits may remain aloft for years, circling the planet like tiny bullets traveling 17,000 mph.

This event brings to mind a Chinese ASAT test in 2007, which also occurred near solar minimum and created a significant debris field of more than 35,000 pieces. That test occured at an altitude of 865 km, with particles ultimately spreading between 200 km and 4000 km. At least one Russian satellite was unintentionally damaged by the debris.



India's test at 300 km altitude has created an upward spray of debris that could threaten the International Space Station only 100 km overhead, according to statements made by NASA Administrator Jim Bridenstine during an April 1st town hall meeting in Washington DC.

"That is a terrible, terrible thing, to create an event that sends debris in an apogee that goes above the International Space Station," he told NASA employees.

Officials say there are 60 trackable fragments of Microsat-R measuring 10 cm across or larger. Of that total, 24 ended up in orbits with high points, or apogees, above the 400 km altitude of the ISS. Low solar activity, which could last for years as the solar cycle ponderously swings through its minimum phase, will help keep these fragments aloft, prolonging their threat to other satellites.

 

[CodeRedR51]

First static fire of StarHopper was successful.

 

[CodeRedR51]

Falcon Heavy launch coming up on Sunday, window opens at 6:36pm EDT. There won't be a huge wait after this one for the 3rd, this exact same booster configuration will be refurbished and re-used for a US Air Force satellite launch in June. (current target)

Static fire was postponed until today, so the launch date will slip slightly. Looking at Monday or Tuesday but SpaceX will confirm after the static fire.

 

[Dotini]

This occurred on July 23, 2012 when a powerful coronal mass ejection (CME) eruption missed the Earth but enveloped NASA’s STEREO-A satellite.

Powerful eruption from the surface of the sun captured on May 1, 2013. NASA
A 2013 study estimated that the U.S. would have suffered between $600 billion and $2.6 trillion in damages, particularly to electrical infrastructure, such as power grid, if this CME had been directed toward Earth. The strength of the 2012 eruption was comparable to the famous 1859 Carrington event that caused widespread damage to telegraph stations around the world and produced aurora displays as far south as the Caribbean.

 

[Dotini]

Nothing off the table when it comes to using Falcon Heavy for urgent lunar missions. Very informative, even funny vid:




Interim Cryogenic Propulsion Stage

 

[CodeRedR51]

Speaking of Falcon Heavy, launch was delayed due to weather.

6:36pm EDT

 

[Danoff]

Nothing off the table when it comes to using Falcon Heavy for urgent lunar missions. Very informative, even funny vid:




Interim Cryogenic Propulsion Stage

Sounds like NASA is still expecting to use SLS, and it's easy to see why.

 

[ProjectWHaT]

 

[Obelisk]

This is truly a historic moment in time.

 

[Tired Tyres]

Could have at least got it in focus....

Was going to post this myself since my phone was getting news updates about it. There's supposed to be another one at some point. Sagittarius A.

 

[Dennisch]

Sagittarius A.

Which is a lot closer! 55 million lightyear vs 10000. Perhaps that one will a bit more in focus.

And we need that goddamn Webb telescope in the skies!

 

[Danoff]

Ok so... why does it look like a ring? Shouldn't the event horizon be a 3D phenomenon?

My guess at the moment is that this image is exposed to reveal the relative lack of brightness in the middle and the relative increase in brightness as you look through more light around the edges.

Edit:

My second guess is that the light from the edges is not affected the same way by the gravity of the black hole given its trajectory. So light from the event horizon is never going to move straight at you from a black hole because there is nothing emitting light from there. The only light that will ever reach you from one would have to be light that was bent around the side and didn't go in.

Edit 2:

So it looks like a ring no matter where you're standing!

 

[ProjectWHaT]

Veritasium did a very well done very visually explaining the image

 

[Famine]

Ok so... why does it look like a ring? Shouldn't the event horizon be a 3D phenomenon?

The event horizon will be, but the matter around it will still be in its original orbital plane as it spirals in towards its doom, heated to the point of emitting x-rays - which would mean we're looking at the black hole perpendicular (or close to it) to its orbital plane.

 

[wfooshee]

Are we looking at a polar view in this image? My understanding is that this is the M87. i would expect a ring in a polar view. A view of our own galactic core black hole would be edge-on to the disc, not to mention all the crap between us and it. (Kind of weird to talk about the crap between us and something only a fraction of the distance, but looking through the galaxy as opposed to out of it is a completely different thing. Kind of like looking through a window pane edgewise.

EDIT - tree'd twice while I typed...

 

[Exorcet]

Ok so... why does it look like a ring? Shouldn't the event horizon be a 3D phenomenon?

I think we might be seeing an accretion disk, though I'm not entirely sure. Black Holes tend to rotate like most other astronomical objects, so most of the infalling material will orbit in a particular plane. That's my own casual understanding at least.

 

[Danoff]

The event horizon will be, but the matter around it will still be in its original orbital plane as it spirals in towards its doom, heated to the point of emitting x-rays - which would mean we're looking at the black hole perpendicular (or close to it) to its orbital plane.

Are we looking at a polar view in this image? My understanding is that this is the M87. i would expect a ring in a polar view. A view of our own galactic core black hole would be edge-on to the disc, not to mention all the crap between us and it. (Kind of weird to talk about the crap between us and something only a fraction of the distance, but looking through the galaxy as opposed to out of it is a completely different thing. Kind of like looking through a window pane edgewise.

EDIT - tree'd twice while I typed...

I think we might be seeing an accretion disk, though I'm not entirely sure. Black Holes tend to rotate like most other astronomical objects, so most of the infalling material will orbit in a particular plane. That's my own casual understanding at least.

This is supposed to be the event horizon. @ProjectWHaT posted the explanation, and my second guess was pretty close!!

Edit:

Ok so I think this is actually the disk and the event horizon all rolled into one image. But the disk looks ring-shaped from all vantages just like the event horizon for the same reason - the only light rays that make it to your eyes are the ones that escaped, essentially from around the edges.

 

[Danoff]

 

[Carbon_6]

Veritasium did a very well done very visually explaining the image

The second he mentioned looking at the accretion disk from an angle, the black hole from Interstellar immediately came to mind.

 

[Famine]

This is supposed to be the event horizon.

From what I understand, the black bit in the middle "is" the event horizon, but the bright bit is the x-ray photons from the inside of the accretion disk.

I say "is", because due to gravitational lensing you can "see" not just the bit facing you, but the back too (I say "see" because you can't see it because it's a black hole). And actually you can a bit of the front outside the back. And so on, up to a point that I can't remember but it's just short of where the accretion disk starts.

I get a bit fuddled with the effects of gravitational lensing on the accretion disk. I think there's a bright bit because that part of the disk is moving towards us at "very fast" and the bit opposite is moving away from us at the same speed - but I can't remember if that means we're looking at the equator or the pole. I thought it was the pole because it's circular, but it might be edge on too; you should be able to see the front and the back at the same time... I think.

So from the inside out it should be event horizon (all of it, several times), then x-ray or gamma ray photons emerging from the space between the accretion disk and the photon sphere (there's a radius smaller than the accretion disk limit but larger than the photon sphere, which I also can't remember), then x-ray photons from the inside of the accretion disk.

But then black holes turn my head inside out.

 

[Danoff]

From what I understand, the black bit in the middle "is" the event horizon, but the bright bit is the x-ray photons from the inside of the accretion disk.

I gather from the video that the event horizon is located in the black bit. But light that has bent around the black hole and reached us (which is what I'd think of as taking a photo of the event horizon of a black hole) is the ring. Additionally in the ring is light from the accretion disk that has bent around the black hole and reached us. And also potentially light which was not (wildly) bent by the black hole and reached us more "directly".

but I can't remember if that means we're looking at the equator or the pole.

I think it necessarily appears this way regardless of your vantage point.

Edit:

Here's a simulation of the appearance either face on (left 2) or edge on (right 2). If you look at the GRMHD version you can see the ring in both as discussed in the video that was posted earlier. He also talks about why you'd see a line across the middle (because there's a disk there of course) and why it's brighter on one side (moving toward vs. moving away).

 

[ProjectWHaT]

The second he mentioned looking at the accretion disk from an angle, the black hole from Interstellar immediately came to mind.

Yeah Interstellar is incredibly accurate because they hired a bunch of physicists to make sure it was good. They even ended up writing a bunch of scientific papers from it

 

[Carbon_6]

Yeah Interstellar is incredibly accurate because they hired a bunch it physicists to make sure it was good. They even ended up writing a bunch of scientific papers from it

When it came to creating the black hole (as well as the wormhole), the special effects team were set equations generated by Kip Thorne (astrophysicist and consultant for the film) based on real world physics. What the rendering software produced was initially thought to be wrong, but in actual fact turned out to be a correctly modelled phenomenon inherent in the math he'd supplied – the most accurate simulation ever of what a black hole would look like.

 

[ProjectWHaT]

 

[CodeRedR51]

Launch day. Rumors of a slight delay ~2 hours. Will confirm.

 

[Novalee]

The case for a multi-verse


https://www.forbes.com/sites/startswithabang/2019/03/15/this-is-why-the-multiverse-must-exist/

The Multiverse is an extremely controversial idea, but at its core it’s a very simple concept. Just as the Earth doesn’t occupy a special position in the Universe, nor does the Sun, the Milky Way, or any other location, the Multiverse goes a step farther and claims that there’s nothing special about the entire visible Universe.