Zitat von ZRDiese chinesische Mission schließt damit eng an die vergleichbare Mission DART der amerikanischen Raumfahrtbehörde NASA an, dem Double Asteroid Redirection Test, die seit dem 24. November 2021 unterwegs zum Asteroiden Dimorphos ist. Dabei handelt es sich um die kleinere Hälfte eines Doppel-Asteroiden, gewissermaßen den Mond des Asteroiden Didymos. Während Didymos einen Durchmesser von 780 Metern aufweist, mißt sein 2003 entdeckter Trabant nur rund 160 Meter. Zwischen dem 26. September und 1. Oktober 2022, in gut 6 bis 7 Wochen also, soll die 500 kg schwere DART-Sonde, nach dem Aussetzen mehrere Kleinsatelliten („Cubesats“) zur Missionsbeobachtung, mit einer Geschwindigkeit von 6,6 Kilometern pro Sekunde, auf dessen Oberfläche einschlagen. Auch hier ist es das Ziel der kosmischen Tontaubenschießens, festzustellen, ob sich durch den Impakt eine Änderung der Umlaufbahn ergibt – und es sich möglicherweise lohnt, diesen Ansatz weiter zu verfolgen, um im Fall eines tatsächlich drohenden irdischen Einschlags praktische Maßnahmen dagegen treffen zu können.
Hier gibt es dazu eine Missionsübersicht sowie einen Countdown:
Zitat Double Asteroid Redirection Test NASA'S FIRST PLANETARY DEFENSE TEST MISSION
Countdown to DART's Impact on September 26, 2022, 7:14 p.m. EDT 12 Days : 09 Hours : 22 Minutes : 53
Zitat DART Impactor DART is a low-cost spacecraft. The main structure of the spacecraft is a box with dimensions of roughly 1.2 × 1.3 × 1.3 meters (3.9 × 4.3 × 4.3 feet), from which other structures extend to result in measurements of roughly 1.8 meters (5.9 feet) in width, 1.9 meters (6.2 feet) in length, and 2.6 meters (8.5 feet) in height. The spacecraft has two very large solar arrays that when fully deployed are each 8.5 meters (27.9 feet) long. DART will navigate to crash itself into Dimorphos at a speed of approximately 6.1 kilometers (3.8 miles) per second. The total mass of the DART spacecraft was approximately 1,345 pounds (610 kilograms) at launch and will be roughly 1260 pounds (570 kilograms) at impact. DART carries both hydrazine propellant (about 110 pounds, or 50 kilograms) for spacecraft maneuvers and attitude control, and xenon (about 130 pounds, or 60 kilograms) to operate the ion propulsion technology demonstration engine.
Zitat von 22:47 BST, 14 September 2022 | UPDATED: 09:14 BST, 15 September 2022Meteor streaks across Scotland’s skies ‘so low you could HEAR it’ leaving locals transfixed
A large meteor has been spotted over Scotland and the north of England.
Video shot form a back garden in Motherwell shows large bright object flying from let to right an a downwards angle followed by a long tail.
The UK Meteor Network has received more than 200 public reports about a fireball in the sky. A couple of their cameras caught the image.
Many people reported hearing a loud bang as the object entered the Earth's atmosphere and shot past the sound barrier.
According to initial reports the meteor has heading from the south west over the island of Ireland and across to Scotland.
Alan McGowan, of Dunblane, Stirlingshire, said: 'I saw it arc slowly across the night sky as I drove through Dunblane with my dad around 10pm. It was a huge burning ball of green with an orange flaming tail. It was amazing to see. At first we thought it was a crashing plane or helicopter then realised it was likely a meteor.'
One video shot in Dublin saw the meteor lighting the night's sky green.
Some witnesses claimed that the object crashed north of Glasgow although there has been no proof of an impact.
Zitat Residents in Scotland and Northern England were stunned to witness a likely meteor gliding through the sky, describing the event as “unbelievable” and “stunning”.
Als ich das gelesen habe, musste ich an Shakespeare denken: “When beggars die, there are no comets seen. The heavens themselves blaze forth the death of princes.”
Wie passend, dass der größte Meteoritensturz ausgerechnet zeitgleich passiert mit dem dortigen Tod der Königin...
Zitat von Ulrich Elkmann im Beitrag #2 Hier gibt es dazu eine Missionsübersicht sowie einen Countdown:
Zitat Double Asteroid Redirection Test NASA'S FIRST PLANETARY DEFENSE TEST MISSION
Countdown to DART's Impact on September 26, 2022, 7:14 p.m. EDT 12 Days : 09 Hours : 22 Minutes : 53
Da sieh' mal einer an: Analog Science Fiction - Science Fact, September/October 2022. Das bekommt man auch nicht oft zu lesen: Eine Science-Fiction-Story, die buchstäblich nächsten Montag spielt.
Zitat von Tangent Online, 22 September 2022, Mike BickerdikeThis bimonthly issue of Analog has a lot on offer, containing a novella by Michael Cassutt, 4 novelettes, 15 short stories and 2 pieces of flash fiction.
“Shepherd Moons” by Jerry Oltion, is a novelette in which the real-life impact of a spacecraft with an asteroid, occurring this year, is given a fictional treatment. The DART spacecraft (Double Asteroid Redirection Test) is being undertaken by NASA to determine how much an asteroid can be redirected by collision, with impact due on 26th September 2022. In Oltion’s story based on these contemporary events, the impact and damage to the asteroid reveal an alien presence in our solar system, which is followed up by a manned mission to the asteroid. It’s quite a nice idea, but it unfortunately fails to translate into a particularly interesting or believable story. The protagonist doesn’t convince as a lead astronaut, and the tale would have been more engaging if the prose axiom of ‘show don’t tell’ was more often adhered to. Overall, rather a missed opportunity for a cool real-life tie-in.
Zitat von Analog, Sept.-Oct. 2022"Shepherd Moons" by Jerry Oltion
It wasn’t every day that NASA whacked an asteroid with a half-ton space probe. DART was designed to test how much influence an impact would have on the asteroid’s orbit, but it was also proof of concept for much more ambitious missions to follow, some of which might be crewed depending upon what they discovered tonight. Didymos was an Earth-crossing asteroid with a two-year period, relatively easy to reach and relatively easy to return from after an extended stay. If NASA ever sent a mission out there, Priya planned to be on board.
The mission clock ticked over to 6:30. Forty-four minutes to impact. Didymos was a bright speck in the center of the field, still too small to show a disk. But the probe was approaching at over four miles per second, and as they watched, a dimmer speck separated from the bright one. Dimorphos, Didymus’s tiny moon. That was the actual target. DART would strike it head-on as it swung around in its orbit, slowing it down by a smidgen, enough for telescopes on Earth to detect the difference in its period after a few more orbits. And that sudden slowdown would change the orbit of the larger companion by an even smaller smidgen. Not enough to matter, but it was a proof-of-concept mission, a demonstration that we could alter the orbit of an asteroid if we needed to.
A cheer filled the room as the two bright dots separated. “Right on schedule,” Mark said. So far the mission was going nominally. It was entirely automated at this point, with the probe thirty-six light-seconds away, so if anything went wrong, there would be little the controllers could do to correct it.
“It’ll be switching guidance from Didymos to Dimorphos,” Priya said. And as she spoke, the view gave a little jerk. “That was the thruster.”
The mission communicator a few stations down the row said, “The probe has achieved a navigation lock on Dimorphos. All systems are ‘go.’ Forty-one minutes to impact.”
Priya said, “That means the probe is . . . almost exactly ten thousand miles out.” ... The two specks drew apart on the monitor as the probe closed in. Mark said, “I read somewhere that the number of Earth-grazing asteroids that are binary is way higher than the number of binaries out in the main asteroid belt. Weird statistic.”
Priya said, “It’s the YORP effect. Sunlight on a rotating body makes it spin faster, and it eventually breaks apart. Sunlight is stronger on near-Earth asteroids than on main belt asteroids.”
Mark laughed. “I was just going to guess that.”
“Sure you were.”
Priya took a sip of coffee and kept the mug in her hand for warmth. She had become shivering cold in the last few minutes.
They watched the asteroids draw apart, Didymos finally becoming a disk rather than just a point of light. It was roughly spherical, with boulders and depressions more or less at random. Dimorphos was much smaller, only five hundred feet, a fifth the size of Didymos, so they didn’t see detail until just a couple minutes before impact. When they did, all that stood out was just a bright spot on a surprisingly smooth, round surface.
“That’s weird,” Priya said. “It’s more spherical than Didymos. You’d expect the smaller one to be more ragged. Less gravity to pull things together.”
It was growing fast now. Didymos slid off to the side of the screen, leaving Dimorphos dead center. The bright spot began to take on shape, but that shape was perfectly round. Round with a blister dead center. Sunlight angling in from the side made it obvious that they were looking at a dome. A dome with round ports, dish antennae, and angled black solar panels.
Voices raised all around the control room. “What the hell! That’s artificial! Who put that there?”
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