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1500 questions
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How many pixels could an image of Proxima b taken by James Webb have?
I know it's very difficult for the James Webb Space Telescope to image the exoplanet Proxima b without an external coronograph (I have been told by NASA scientists that they don't know yet whether they will be able to do so), but I wonder how it is…
James
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Why will HD 84406 be chosen as the first target for testing JWST?
HD 84406, is a star approximately 241 light-years away in the constellation of Ursa Major. HD 84406 will be the first star to be imaged by the James Webb Space Telescope in order to test the focus of the telescope. The star is a spectral type G…
NeutronCat
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Supermassive black holes at the center of galaxies
The fact is, many, if not most large galaxies have a supermassive black hole at their center. My question is why? Is it because when these galaxies were first formed supermassive black holes were created out of super-dense clouds of matter, which…
Foo Barrigno
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Can an object from a natural process escape earth gravitation?
I'm no expert, but I once studied basic from advanced physics and understand
gravity
action/reaction
escape velocity of 11.2 km/s from the earth surface
escape velocity changing as the object go far away
Karman line for space (100 km)
What I want…
KeitelDOG
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I live in an area with a lot of light pollution, how can I view the stars without building an observatory?
I live in an urban area with a lot of light pollution and very little garden space. On a clear night I can see most of the sky and the brighter stars are visible.
I can't build an observatory - I don't have the space (let alone the money required) -…
ChrisF
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Is it suspicious that gravitational waves propagate at the speed of light?
Thinking about gravitational waves and the fact that they propagate at the speed of light, I was wondering if it isn't suspicious - the speed of light I mean. Does it perhaps point to something fundamental about the spacetime? Is there maybe some…
PunchyRascal
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How often do comets survive passage by the Sun?
I had heard that comet ISON might not survive a close pass by our Sun, and I was curious about the odds of how other comets had fared. So, how often do other comets survive a close pass by our sun? Also, are there any connections between a comet's…
Sarah Szabo
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Is S2 still the fastest known star in the galaxy?
Wikipedia's entry for the star S2 says that it has
the fastest known ballistic orbit, reaching speeds exceeding 5,000
km/s (11,000,000 mph, or 1⁄60 the speed of light) and acceleration of
about 1.5 m/s2 (almost one-sixth of Earth's surface…
Connor Garcia
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Why won't the Sun set for days at N66.2 which is below the arctic circle?
Correct me if I am wrong, but if we count sunsets by the center of the Sun apparently crossing the horizon then the Sun is supposed to set every day at latitudes under the arctic circle. (Yes if you count in the disc then adjust by 0.27 degrees.)
I…
mr_tuna
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Why are most discovered exoplanets heavier than Earth?
Looking at all discovered exoplanets (4393 exoplanets), I found than only 17 of them (less than one percent!) have masses less or equal to Earth's mass. Why so?
Is it because it is very difficult to discover an exoplanet of a low mass?
Is it…
Peter
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If suddenly "knocked" or perturbed from its orbit, would gravity eventually return the Earth to its original orbit?
If suddenly "knocked" or perturbed from its orbit, would gravity eventually return the Earth to its original orbit?
I am curious as to whether this is even possible.
It seems to me that since the orbit is based on gravity, the same gravity will pull…
ifeoluwa king
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Solar Analemma - but with a star instead
We (homeschool students and I) are trying to find the answer to this question. Does a star also create Solar Analemma figure 8 when photographed daily for a year?
Has anyone published an experiment where the same star is photographed every night at…
Bookaholic
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20
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What is behind the Great Red Spot's longevity?
On Earth, storms can last a few days. The Great Red Spot on Jupiter is a storm that has been going on for more than 400 years now. What is different on Jupiter that makes it possible for storms to last so long?
usernumber
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20
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Was the Geocentric Model correct at all?
It's easy to find resources stating that the heliocentric model is right and geocentric is wrong.
But how wrong was it? Was it correct in any way?
It was built on incorrect assumptions, but despite that - was it of any use to describe the apparent…
Voy
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When was the martian dichotomy first observed?
The North and South hemispheres of Mars are very different one from another. They have different elevations, different crust thickness, different surface ages. This is known as the martian dichotomy.
When was this striking difference between the two…
usernumber
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