Quick 🧵 on concerns around AST SpaceMobile's massive new satellite, BlueWalker 3, launching tomorrow.

The experimental satellite will test if AST can directly beam 4G/5G from space to individual mobile phones.

This requires a huge antenna, which could be extremely bright... 1/ The satellite will launch on a SpaceX Falcon 9 rocket tomorrow evening from Florida.

After launch it will be raised to an altitude of 500km, where it will unfurl its huge antenna, 693 square feet in size, or half a tennis court.

It is large, flat, and could be v reflective. 2/

Tonight, at 12.11am UK time, China will attempt to land a rover on Mars.

If successful, it will become only the second nation after the US to operate on the Martian surface (the Soviets came close).

It's a big deal, so I thought I'd lay out a few things in a little thread (1/x) - The mission, Tianwen-1, consists of an orbiter and rover. The latter is named Zhurong after a mythological god of fire

- The landing site is Utopia Planitia, the largest impact basin on Mars. This was also the landing site for NASA's Viking 2 mission in 1976 (2/x)

So, a small helicopter NASA is about to fly on Mars might do something pretty awesome.

The blades of the helicopter might electrically charge the Martian dust, causing it to...

Glow in the dark!

Words by me @NewScientist and short thread

(1/x)

newscientist.com/article/226767… The small helicopter, called Ingenuity, is part of the @NASAPersevere rover landing on 18 Feb.

It'll perform up to five flights in a 30-day window starting in March, lasting up to 90 seconds each.

These are the first attempts at flight on another planet.

(2/x)

So, this is an incredible discovery.

We may have our best evidence yet for a moon orbiting a planet outside our Solar System.

And it comes from... a dead star eating the frozen moon's remains.

Story by me @NewScientist, and thread to follow.

(1/n)

newscientist.com/article/226695… Recently, a team of scientists used the Keck Observatory in Hawaii to observe the white dwarf GALEX J2339 – a remnant of a star like our Sun reaching the end of its life.

And they found something odd – loads of the element beryllium, 500 times more than they expected.

(2/n)

So, a story I've been working on...

The FCC may have wrongly ignored US environmental law in approving SpaceX's Starlink mega constellation (and other satellites). Were it to be sued, it would likely lose.

Story below @SciAm, and thread to follow (1/)

scientificamerican.com/article/the-fc… Astronomers and members of the general public have been alarmed by the brightness of SpaceX's Starlink satellites.

Adding up to 42,000 bright points of light into orbit, mega constellations like this have the potential to change our night sky forever. (2/)

So, I've just had it confirmed from another ESA source that #SpaceX refused to move their #Starlink satellite when they were alerted to the risk of collision with #Aeolus, which was 1 in 1,000, ten times higher than the threshold for a collision avoidance manoeuvre. (1/5) SpaceX sent a short email to ESA saying they would not move their satellite. It's not clear why - they didn't mention if the satellite was active or not, apparently (ESA weren't even aware what the satellite was). (2/5)

There is a Japanese spacecraft called Hayabusa 2 (@haya2e_jaxa) arriving at an asteroid in the next few days.

It hasn’t had a lot of love or attention yet. But this mission is FRICKING AWESOME. I’m going to tell you why.

Thread (1/n) Hayabusa 2 is a mission to return material from inside an asteroid called Ryugu to Earth, something that's never been done before (2/n)