Questions tagged [planetary-science]

The study of planets, asteroids, comets, etc, including weather, geology, composition, etc. This tag should be used when the focus of the question is on the the science of a non-Earth non-star natural object, and not used when designing spacecraft to cope with said challenges.

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9
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How do domes in lunar impact melts develop, and might they be hollow?

On the floors of young craters of the Moon, smoothly rounded domes are visible in some spots. Lalande crater has 4 of them, each around 200 m across. Here are less regular ones on the floor of ...
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304 views

What makes materials on the Moon look so different when the sun is high?

The surface of the Moon looks very different in orbiter images taken at local noon than it does in images from other times. Here are two examples of the same places in Lalande Crater. In each image, ...
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What are the contributions of ancient Indian astronomers in mapping of the solar system and galaxies?

In the history of astronomy we usually come up with the name of European astronomers like Kepler and Galileo. Earlier Indian astronomers, for example Aryabhata and Bhaskaracharya, are not usually ...
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260 views

Why does the Moon's Anaxagoras crater seem sort of jumbled?

Now that very high resolution imagery of the Moon's whole north, above 60oN, can be viewed on one giant awesome zoomable map, I've been taking a close look at a number of craters. Anaxagoras sticks ...
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How are marsquake epicenters determined using only one seismometer?

This tweet says: Cerberus Fossae is the first active seismic zone ever discovered on Mars. Located about 1,600 kilometers east of @NASAInSight lander, this huge extensive tectonic structure was the ...
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85 views

How did scientists experimentally confirm that Saturn's ravioli-shaped moons had highly porous surfaces?

The NASA News article NASA's Cassini Finds Saturn's Rings Coat Tiny Moons says: The new research, from data gathered by six of Cassini's instruments before its mission ended in 2017, is a clear ...
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113 views

Probing gas giant planets by descending through a cyclones's “eye”?

On Earth cyclones have regions of calm weather commonly known as eyes. They appear to create tunnels spreading from the top of the atmosphere down to the sea level. Wikipedia article mentions their ...
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145 views

Are we still able to terraform Mars using greenhouse effect?

In the last month, a group from University of Colorado, Boulder, published a paper on Nature Astronomy entitled "Inventory of $CO_2$ available for terraforming Mars", which was highly publicized on ...
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What does “clumps and streams” of hydrogen leaving Mars' atmosphere really mean? Are there images of them?

This excellent answer to Just how huge is Mars' cloud of hydrogen? links to the 14 October 2014 Nature News item "Hydrogen Cloud Blows Off Mars", by Alexandra Witze, https://www.nature.com/news/...
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When were the presence of specific elements on asteroids first identified?

Is there an approximation on when scientists first found out about certain elements on asteroids? What about gold in particular?
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113 views

What would happen in this cavern on the Moon?

Imagine a large cavern on the moon, around the theoretical size limit determined by Purdue university - about 1.5 kilometers high, and 5 kilometers across on the floor. This cavern is a kilometer or ...
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How were Mars' zero elevation datum defined? What are their shapes?

Discussions on Boiling ponds and pools on Mars? led me to Wikipedia's Mars; Geography and naming of surface features which says: Because Mars has no oceans and hence no "sea level", a zero-...
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Is planetary impact testing planned for the InSight Mars lander's seismometers?

The question How could InSight's seismometers be intentionally and meaningfully “pinged”? is a hypothetical and has several good speculative answers. But here I'd like to ask specifically about any ...
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127 views

3D celestial puzzle; why InSight's two RISE horns point slightly south of east, and north of west?

@karthikeyan's excellent answer links to The Rotation and Interior Structure Experiment on the InSight Mission to Mars (Folkner, W.M., Dehant, V., Le Maistre, S. et al. Space Sci Rev (2018) 214: 100. ...
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Career in Planetary Science with an Engineering background

I am passionate in achieving a career in Planetary Science. I have a bachelor's degree in mechanical engineering background with an average academic record. I want to pursue a career in Planetary ...
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How does Mars have a Bow Shock and proton aurora? What is a hydrogen corona?

I just saw the NASA video Mars Proton Aurora below and I'm confused, (which by itself is unremarkable). Without a planetary magnetic field, what force produces a bow shock in the solar wind at Mars, ...
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107 views

Surface material on Saturn's moon Rhea

The Cassini mission has made several flybys of Saturn's second largest moon, Rhea. Do we have any data about that moon's surface geochemistry? I do know there is a thin Oxygen/Carbon Dioxide ...
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What Jovian system science targets would be suitable for Jupiter gravity assist flyby missions with other primary purposes?

Flying by Jupiter for gravity assist, and with the Oberth effect bonus, has been used for multiple missions to other outer planets and to comets. And has potential for use even for missions aiming at ...
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90 views

Origin and evolution of Earth's atmosphere

The focus of my question pertains to the natural chemical and biological mechanisms which evolved the atmosphere on Earth as we have known it up to modern times (excluding human activity), and how it ...