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98

The comet's tail always points away from the Sun. Yes, even when the comet is heading back into the outer solar system. This is because the tail isn't a 'trail' of where the comet has been, like a rocket exhaust or contrail, but instead it's gas, ice and other debris blown off by the stellar wind. (There's actually two tails, one made of charged particles, ...


37

I do disagree with the other answers, not on the result, but on the reason. You don't need to go faster than the speed of light to pass through multiple stars in a few seconds. Putting aside the problems of accelerating to a high enough speed in a human lifetime without being crushed by G forces, storing enough fuel for that (what would you use as fuel? ...


15

If you're the comet, the way to hit Earth is not to head directly for it. That's because Earth is orbiting the sun: you need to aim at where Earth will be, not where it is right now. For example: By Phoenix7777 - Own work Data source: HORIZONS System, JPL, NASA, CC BY-SA 4.0, Link This shows a transfer orbit from Earth (blue) to Mars (green), but the basics ...


15

While those movies probably do it because that's how comets are commonly depicted, it might not be that inaccurate. Remember that the Earth itself is moving around the Sun, so if a comet is heading for Earth, that means it's heading for a point where Earth will eventually be, not where it currently is. It would therefore be possible to see such a comet be &...


10

The MAHLI camera of Curiosity may focus from infinity down to only 18.3 mm working distance. At minimal distance the resolution is 13.9 µm per pixel. It may image objects of some tens of meters in size down to only 22 by 17 mm. The Sherloc camera of the Mars 2020 Rover has a similar minimal object size of 23 by 15 mm. A microscope with a magnification of ...


7

July 20, 1976, Mars, Viking 1 lander. In the article "Viking gas chromatograph–mass spectrometer" by Rushneck et al, Review of Scientific Instruments 49:817-834 (1978), section G (pp. 828-9) describes the GCMS's soil loader and pyrolyzer subassembly, which accepts a pulverized soil sample, loads it into an oven, and then seals and heats the oven. ...


6

The Vega 1 balloon that entered the atmosphere of Venus on June 11, 1985, had LEDs on the anemometer: The diameter of the rotating anemometer was 25 cm. The rotor was mounted on ball bearings, and rotation was monitored by a coded disk and two sets of light-emitting diode (LED) light sources and solid-state detectors. Source: VEGA Balloon System and ...


5

For STS payload induced enviroments, grab yourself a copy of the Space Shuttle User's Handbook and you will find plenty of data starting on page 31 of the pdf. Vibration, noise, thermal, pressure (and lack thereof), all the usual suspects.


4

It helps to suppose that you're flying your ship somewhere closer to a galactic nucleus than we are. Sure, the nearest star to us (after the Sun) is several light years away, but if you get within a few light-years of the center of the Milky Way, the average distance between stars is less than 0.02 light year (1/250th of what other answers are taking as the ...


3

The meteorite is part of the SuperCam Calibration Target (SCCT) on Perseverance. From the paper "SuperCam Calibration Targets: Design and Development": As a nod to the notion of return samples that this mission prefigures, and for outreach purposes, we have installed a ∼11×9×1.25 mm slab from a Martian meteorite (ref. North West Africa, NWA 10170) ...


2

May 25, 2008, Phoenix Mars Lander. (Surely there's an earlier lunar example?) The Robotic Arm Camera took an image of the Robotic Arm scoop using its red LED (Light-Emitting Diode) lamp.


2

Yes, via a light-speed U-turn When traveling at speeds close to the speed of light, stars appear to conglomerate into a single blurb in front of a spacecraft (artistic example). When slowing down, those stars will appear to move back to their 'normal' rest positions, and diminish in spectrum (i.e. they will appear to undergo redshift). This means that stars ...


2

Even though the question has already been mostly answered, here is more information about current Lunar Ranging activities. The EUROLAS Data Center (EDC) of the Deutsches Geodätisches Forschungsinstitut at Technische Universität München has a nice website with an API to find laser ranging data. The data are the same than on the CDDIS website as the data ...


1

July 20, 1976, Mars, Viking 1 lander. (You're really not going to like this one.) The lander's cameras included an array of 12 photodiodes to measure various things. One reference even plots each photodiode's spectral sensitivity; the abstract of another paper gives enough evidence for their existence. But every photodiode also acts as a (rather inefficient) ...


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