A black hole, exoplanets. It has always been inferred.
Apparently, there have been strange sightings, but there has been no evidence or proof that an extraterrestrial being (alien) has actually been seen.
I have usually seen them quoted in kilometers.
Since the beginning of astronomy. Astronomers are ALWAYS looking for new things.
As astronaut travels into outer space and some have been killed doing so. Most astronomers stay on the planet Earth and look up into space. There have been astronauts who are astronomers, but, most astronomers are not astronauts. There have been tens of millions of astronomers looking up at outer space, but, only a few hundred astronauts. No, they are not the same.
'Dark matter' and 'dark energy' have not been observed or proven yet.
The Oort Cloud
Yes (since 1801).
Yes (since 1801).
It has been seen by people for over 2000 years. It is not known who was the first person to actually see it. Many ancient astronomers would have seen it. It was not known as Halley's Comet then. It got that name when Edmond Halley, and English astronomer, predicted it would return in 1759. It is seen about every 75 or 76 years from Earth.It has been seen by people for over 2000 years. It is not known who was the first person to actually see it. Many ancient astronomers would have seen it. It was not known as Halley's Comet then. It got that name when Edmond Halley, and English astronomer, predicted it would return in 1759. It is seen about every 75 or 76 years from Earth.It has been seen by people for over 2000 years. It is not known who was the first person to actually see it. Many ancient astronomers would have seen it. It was not known as Halley's Comet then. It got that name when Edmond Halley, and English astronomer, predicted it would return in 1759. It is seen about every 75 or 76 years from Earth.It has been seen by people for over 2000 years. It is not known who was the first person to actually see it. Many ancient astronomers would have seen it. It was not known as Halley's Comet then. It got that name when Edmond Halley, and English astronomer, predicted it would return in 1759. It is seen about every 75 or 76 years from Earth.It has been seen by people for over 2000 years. It is not known who was the first person to actually see it. Many ancient astronomers would have seen it. It was not known as Halley's Comet then. It got that name when Edmond Halley, and English astronomer, predicted it would return in 1759. It is seen about every 75 or 76 years from Earth.It has been seen by people for over 2000 years. It is not known who was the first person to actually see it. Many ancient astronomers would have seen it. It was not known as Halley's Comet then. It got that name when Edmond Halley, and English astronomer, predicted it would return in 1759. It is seen about every 75 or 76 years from Earth.It has been seen by people for over 2000 years. It is not known who was the first person to actually see it. Many ancient astronomers would have seen it. It was not known as Halley's Comet then. It got that name when Edmond Halley, and English astronomer, predicted it would return in 1759. It is seen about every 75 or 76 years from Earth.It has been seen by people for over 2000 years. It is not known who was the first person to actually see it. Many ancient astronomers would have seen it. It was not known as Halley's Comet then. It got that name when Edmond Halley, and English astronomer, predicted it would return in 1759. It is seen about every 75 or 76 years from Earth.It has been seen by people for over 2000 years. It is not known who was the first person to actually see it. Many ancient astronomers would have seen it. It was not known as Halley's Comet then. It got that name when Edmond Halley, and English astronomer, predicted it would return in 1759. It is seen about every 75 or 76 years from Earth.It has been seen by people for over 2000 years. It is not known who was the first person to actually see it. Many ancient astronomers would have seen it. It was not known as Halley's Comet then. It got that name when Edmond Halley, and English astronomer, predicted it would return in 1759. It is seen about every 75 or 76 years from Earth.It has been seen by people for over 2000 years. It is not known who was the first person to actually see it. Many ancient astronomers would have seen it. It was not known as Halley's Comet then. It got that name when Edmond Halley, and English astronomer, predicted it would return in 1759. It is seen about every 75 or 76 years from Earth.
The Oort Cloud has not been directly observed by astronomers, while both the Main Asteroid Belt and the Kuiper Belt have been observed and studied. The Oort Cloud is a theoretical region of icy bodies beyond the Kuiper Belt, and its presence is inferred from the trajectories of some comets.
Lots of things have not actually been seen. One such thing are black holes - because according to theory, they CANNOT be seen (at least, the Hawking Radiation would be way too weak to be seen); however, due to things happening in the surroundings of the black hole (basically, the accretion disk), some black holes are the brightest objects of the Universe!
He has been in 3 recorded movies and 2 movies that were actually seen by the public
examining life as it is actually lived and recording what has been seen honestly
Only astronauts have been to the moon.
Apparently, there have been strange sightings, but there has been no evidence or proof that an extraterrestrial being (alien) has actually been seen.
I have usually seen them quoted in kilometers.
Because in the sky it looks as if the sun is moving, but actually, the earth is moving but you can't feel it.