The University of Texas at Arlington

The University of Texas at Arlington

UTA Planetarium

UTA Planetarium

Ask the Astronomer Q&A

Tag: "astronomy"

  • I received an email saying that we will see Mars as big as the moon on August 27, 2010. Is this true?
  • No, this is not true. The emails started circulating in 2003 when Mars made its closest approach to Earth. It was closer than it had been in 60,000 years! But, because the distances between Mars and Earth is so great (at and average of 46.5 million miles away) and their size so small (Mars is only half the size of Earth), Mars can never look as large as the Moon. That year, it appeared as a very bright red dot in the sky. Mars is visible this month in the Western part of the sky after sunset. It will appear as a red dot low in the sky. If you want to read more about this email hoax and others we see, check out these great articles on our website!

    (Tags:  astronomy  earth  light  mars  moon  planet  solar system)
  • I was wondering if you could recommend a good telescope to get a better look at space. I don't mean a very expensive one, but a reasonable one to get a good look at the stars, planets.
  • If you are just beginning to use a telescope for enhancing your stargazing experience, we would recommend the Celestron FirstScope, which we have available in our gift shop for $60. This is a table-top telescope with a 3-inch diameter, perfect for viewing the planets and bright deep space objects, such as the Orion Nebula and the Andromeda Galaxy. This telescope is easy enough for children to use, but will last a long time. If you would like to get an intermediate or advanced telescope, I would recommend contacting the Texas Astronomical Society at www.texasastro.org. They have a great online resource for finding the perfect telescope for your needs, and experts able to answer all your questions.

    (Tags:  astronomy  jupiter  mars  moon  planet  saturn  solar system  star  telescope)
  • I've always heard about what's OUT in space. But what about celestial objects that may be directly below us. Have we searched down there, or is everything in space at the same relative 'elevation' so to speak?
  • When astronomers talk about what it “out there”, they are not just referring to the objects that are in the same plane as the Earth. We have telescopes and observatories that study objects that are in line with us, but also those that are above and below us as well. Space is 3 dimensions, so we find objects equally scattered about in all directions, and astronomers want to study them all.

    (Tags:  astronomy  observatory  telescope  universe)
  • In pictures of a galaxy, I notice a big bright star in the center, is that really a gigantic star and how come I can't see that star in the night sky of the milky way?
  • First, when you are looking at a picture of a galaxy, you are not looking at our galaxy the Milky Way. The Milky Way galaxy is about 30,000 light years across, a distance far to great for us to reach. So we have never left our Milky Way galaxy to see it from above. Second, what you did see in the galaxy image was probably not one bright star but hundreds. At the center of most galaxies we have found evidence of supermassive black holes (hundreds of times the size of our sun). Orbiting around this black hole are hundreds, even thousands of very large hot stars that would glow very brightly. This is what you are seeing when you look at images of galaxies. Third, let's imagine for a moment that the galaxy image you were looking at was our Milky Way galaxy, and you went looking for the bright object in our sky. You would still not see the bright object at the center. We know this to be true because when we look towards the center of the Milky Way (near the constellation Sagittarius) we can not see the very center because there is a lot of gas and dust, called Interstellar Material, that is blocking our view. The only way that astronomers can study the center of our Milky Way galaxy is by looking at the Infrared light (heat energy) of stars, since it is the only form of energy which does not get absorbed by clouds of gas and dust.

    (Tags:  andromeda galaxy  astronomy  black hole  light  milkyway galaxy  star  universe)
  • There is a bright light every evening to the West. I thought it was a satellite but I have been looking at it since last year. Do you know what it is?
  • What you have been seeing is not a satellite but the planet Venus. Venus appears as the brightest object in the night sky right after sunset, or right before sunrise. Venus is so bright, because of the thick carbon dioxide clouds that reflect a lot of sunlight back to Earth. We only see it near the Sun, because it is closer to the Sun than Earth. Did you know, that many people mistake Venus for a UFO? This is because it can appear to flicker, move and change color in the sky when it is low in the horizon. First time skywatchers also underestimate how bright celestial objects can be in the sky.

    (Tags:  astronomy  light  planet  sun  venus)
  • What is the SOFIA?
  • SOFIA is an acronym for the Stratospheric Observatory For Infrared Astronomy. It is a telescope mounted to a Boeing 747 airplane. The airplane flies high above Earth's atmosphere to study objects in the infrared part of the electro-magnetic spectrum.

    (Tags:  astronomy  electromagnetic spectrum  light  observatory  physics)