The University of Texas at Arlington

The University of Texas at Arlington

UTA Planetarium

UTA Planetarium

Ask the Astronomer Q&A

Tag: "venus"

  • How long would it take to get to Venus going 60 miles per hour?
  • Venus’s distance from Earth varies depending on where each planet it is its orbit around the Sun. The closest that Venus ever gets to Earth is 23.6 million miles. That means that it would take 44.9 years to reach Venus travelling at 60 mph!

    (Tags:  venus)
  • I am led to understand that the Earth has an atmosphere due to the fact we have a magnetic field that deflects the solar wind. It is further my understanding that Mars lost most of its atmosphere (and subsequently most of its water) because the core cooled and Mars lost its magnetic field. Why then does Venus have such a thick atmosphere given that it has no magnetic field combined with the fact that it is much closer to the sun and therefore is exposed to solar wind to a much higher degree than the Earth is?
  • Actually, Earth has an atmosphere because of the size of the planet. Since gravity is directly related to the size (mass) of an object, the larger it is, the more gravity it possesses. Earth’s gravity is able to hold on to the molecules that make up our atmosphere. Mars, being about ½ the size of Earth, has much less gravity. This allowed the atmosphere on Mars to “evaporate” away into space. Venus still has an atmosphere because it is very close in size to Earth, about 90% Earth’s mass.

    (Tags:  earth  gravity  mars  venus)
  • I have an app on my phone that let's me explore the solar system and I noticed that Mercury and Venus don't appear to rotate. Is their rotation just really slow or is there none at all?
  • Mercury and Venus both rotate very slowly. It takes over 58 days for Mercury to rotate once, and 244 days for Venus to rotate once.

    (Tags:  mercury  solar system  venus)
  • 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 size and brightness of the Sun as viewed from the different planets in the Solar System?
  • We have a few simple calculations that you can use to find the size (in degrees) and the brightness of the Sun on each planet. In fact, these calculations will work for the brightness and size of the Sun from anywhere in the universe, as long as you know the distance of the object from the Sun in AU. To find the size of the Sun in degrees: a = 0.5/distance (in AU) where a is the size in degrees and 0.5 is the size of the Sun as seen from Earth. To find the brightness of the Sun as compared to its brightness as seen on Earth: M = 2.5 * log(distance)^2 – 26.74 Where M is the apparent magnitude of the Sun and 26.74 is the magnitude of the Sun as seen on Earth.

    (Tags:  earth  jupiter  mars  moon  planet  pluto  saturn  solar system  star  sun  venus)