Recent comments in /f/space

ttystikk t1_j6tqrbw wrote

Reply to Have you ever thought how/what it would look like to wander through space forever? by Twidom

Humans have absolutely no idea what "forever" feels like.

The human body is frail and does not have the capability to see much of what's out in space- no surprise, since we evolved to live on Earth. Without instruments, you'll see a fair bit but you won't get nearly as much out of the sharp points of light from stars and faint smudges of nebulae as you would with, say, a telescope.

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bad_syntax t1_j6tm79b wrote

Reply to Once-in-a-lifetime green comet makes closest approach to Earth in 50,000 years today by ReverseGarfield

Even if it was clear here, I literally can't go outside.

Everything is just sheet ice. If I took ONE step outside, I'd slide right into my pool, which is 37, and I couldn't get out of it because of the ice. I'd freeze to death. But maybe, just maybe, I could look up and see this?

Naah, I'll wait for some astronomer in Hawaii to take me some pics. Not risking it.

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rogert2 t1_j6tjfkw wrote

Reply to Supermassive Black hole S50014+81 by [deleted]

> How big is the supermassive black hole S50014+81 compared to Earth?

To answer that, we divide the black hole's "size" by Earth's "size." And by "size," I think you mean something like diameter. So, the formula is H ÷ E.

This is a really simple formula, but we have to make sure we're using the same units for it to work.

  • The diameter of Earth is 12,756.3 km.

  • The black hole's diameter is 1,582 AU, which is a unit of length (like meters), but is still a different unit than kilometers.

So, we either have to convert Earth's size from km to AU, or convert the black hole's size from AU to km. (Let's do the latter.)

1 AU = 149,597,870.7 km

So, the size of the black hole is 1,582 × 149,597,870.7 = 236,663,831,447.4 km.

Now that both are in the same units, we can go back to the original formula and plug in our numbers:

H ÷ E becomes 236,663,831,447.4 km ÷ 12,756.3 km = 18,552,701.9 km.

Thus, the black hole is about 18.5 million times as big as Earth.

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Aeredor t1_j6ti2mh wrote

Reply to Supermassive Black hole S50014+81 by [deleted]

I wouldn’t try to measure much in Earth diameters besides other planets. An AU is much more efficient for measuring things the size of a star system, like black holes. (And solar masses is helpful for star sizes of course.) 1 AU = 11,740.7 Earth diameters, so that black hole is like 9 million Earth diameters, if my quick math is correct (not my strong suit lol).

Did I misunderstand your question?

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