Questions tagged [estimate]

Questions asking for approximate results by making an educated, reasonable guess based on the information given.

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22
votes
1answer
2k views

How long between the moment a meteor is first visible and the moment a meteorite hits the ground?

A meteor is usually only visible for a couple seconds at most, but I would guess that it usually stops being visible high above the ground. Meteors often don't make it to the ground as they completely ...
2
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0answers
54 views

How scientists estimated the number of near-Earth supernovae over the last 11 million years?

According to this article on wikipedia, An estimated 20 supernova explosions have happened within 300 pc of the Earth over ...
4
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2answers
82 views

Photometric redshift - empirical methods (machine learning)

I am currently learning about estimation of photometric redshifts with machine learning methods (or empirical methods in general). These methods use the knowledge about the photometry and the ...
6
votes
1answer
102 views

3C273 jet mass estimate

In this picture of 3C273, we can see a jet—estimated to be around 200,000 light-years long—being emitted. I'm trying to find an estimate for the mass of the jet. It's a stream of ...
3
votes
0answers
49 views

In SETI has anyone calculated an estimate of the mean time between observations?

So the Drake Equation, proposed by Frank Drake, is often cited as a means to estimate the number of intelligent civilizations that exist in the observable universe. Initial calculations by Drake ...
5
votes
1answer
163 views

How did Batygin estimate when Planet Nine was ejected?

Konstantin Batygin has estimated that if Planet Nine was ejected, it would have been ejected 3-10 million years after the formation of the Solar System. I'm curious as to how he arrived at this ...
0
votes
2answers
431 views

Number of stars & planets in Milky Way Galaxy?

Is there any specific numbers on stars & planets count on Milky Way Galaxy ?