All Questions
81
questions
3
votes
2
answers
543
views
Is it possible, by monitoring the brightness of stars, to find a “copy of the Earth + Moon” near them?
More than a dozen Earth-like planets have been discovered around nearby stars based on observations of changes in the brightness of their sun as they pass across its disk (transit events). If an Earth-...
- 158
16
votes
3
answers
5k
views
What does the sky look like from the moon?
From pictures taken on the moon, it appears that there are no stars visible in the sky, but I do not know if this is an effect due to cameras.
What is the actual appearance of the sky on the moon?
...
- 161
1
vote
0
answers
97
views
Why does the Moon - which is grey - appear white to us even at daytime?
The color of the Moon as viewed more closely, is grey. But when we see it in the sky it appears white to us. Why?
Although this question has some answers here: Why is the surface of the Moon white? (...
- 411
0
votes
1
answer
69
views
When the new moon will become visible - after how many hours of conjunction
The moon will be totally invisible during Conjunction of moon, sun and earth.
After how many hours of conjunction, moon will be visible from earth.
0
votes
1
answer
52
views
Why is the time difference of equal tide states not 50 minute if one lunar day is 24 hour and 50 minutes?
I do understand that tidal forces are caused by de difference of gravitational force between both opposite points of the earth where a bulge is formed.
I do understand that a lunar day is ruffle 24 ...
20
votes
3
answers
2k
views
Why is it so dark during a solar eclipse?
At a total solar eclipse the sun is barely covered, like right after sunset. So why is it much darker than right after sunset (which allows us to see the corona)?
- 411
3
votes
3
answers
669
views
What is the relationship between crescent moon and position of the sun? [duplicate]
This is a phenomenon that involves the angles between the points of a crescent moon and the apparent position of the sun. Step outdoors on a day and time when you can see the sun and a crescent ...
- 123
1
vote
2
answers
90
views
Will a satellite orbiting the moon have a tidal locked orbit?
Suppose an artificial satellite is launched to orbit the moon. Ignore 3-body problem issues, just assume it follows a roughly titled elliptical orbit relative to the plane cutting through earth's ...
- 111
0
votes
1
answer
275
views
Measuring Sun and Moon distances to the Earth ratio just by observing angles of elevation if upper 50 percent of Moon's surface is bright?
When the next type of calculation was possibly used for the first time? If 50% i.e. upper half of Moon were bright would the Sun-Earth to Moon-Earth distances ratio be calculated from just ...
- 1,815
4
votes
3
answers
11k
views
How big a coincidence is the Sun and Moon having almost equal apparent sizes?
It's consensus that the very similar apparent sizes of the Moon and the Sun as seen from Earth is a coincidence (as already answered in this site).
This provides us with almost exact total solar ...
- 12.5k
-1
votes
1
answer
58
views
I want to know about the synodic and sidereal months. Why is there a difference between the two? [closed]
I want to know about the synodic and sidereal months. Why is there a difference between the two?
19
votes
7
answers
8k
views
What is a simple argument to prove that the stars in the sky are further away from the Earth than the Moon?
How do we know, without using modern equipment, that the stars are further away than the moon in the night sky? Further, is there a simple and actionable argument to prove that this is indeed the case?...
- 2,402
1
vote
1
answer
688
views
Lunar surface brightness
If the Moon is visible against a clear blue sky with a lux value of around 30,000 does it stand to reason that the lunar surface must be brighter than that?
- 11
0
votes
2
answers
211
views
Why is the moon so bright when it is really dark
The moon is bright, and if you were 50 times closer it would be 25 degrees across with the same surface brightness, which would be pretty dazzling. Looking at the moon through a telescope (which ...
- 387
2
votes
0
answers
117
views
How to interpret doppler curve images of Chandrayaan-2 lander?
The frequency transmission data for Vikram, lander of Chandrayaan-2, received by 25 meter Dwingeloo radio telescope is plotted and tweeted by Cees Bassa. Kinks in the Doppler curve are interpreted as ...
- 3,418