Atmosphere vs. Orbit: Space vs Ground Telescopes Quiz

If light travels from a star to a ground telescope, then it must pass through Earth atmosphere. If the atmosphere has moving layers of different temperatures and densities, then the light path is constantly refracted. If the light bends back and forth rapidly, then the star appears to twinkle. Space telescopes are above the air, so the light travels in a straight line without bending.

If we consider the distance to the nearest star, then moving a few hundred miles into orbit is a negligible change. If the distance change is that small, then the star does not look bigger or brighter because of proximity. The actual advantage is getting above the atmosphere, not getting closer to the target.

If Earth atmosphere protects life, then it must act as a shield against high-energy radiation. If X-rays have very short wavelengths, then they are absorbed by the gases in the upper atmosphere. Therefore, if a scientist wants to study X-rays from black holes, then they must place the detector in space.

If a telescope is on the ground, then engineers can drive to it with tools and repair parts. If a space telescope breaks, then it requires a multi-million dollar rocket mission to fix it. Therefore, ground-based telescopes allow for much larger sizes and more frequent upgrades for much less money.

If the air is turbulent, then the image of a star is smeared into a fuzzy blob instead of a sharp point. If astronomers want to measure the quality of the sky at a specific location, then they use the term seeing. Therefore, better seeing means a steadier atmosphere and sharper images.

If the atmosphere causes blurring and absorbs certain types of light, then being higher up means there is less air above the telescope. If there is less air and less water vapor, then the images are clearer and more light reaches the mirror.

If we can measure how the atmosphere is bending light in real-time, then we can use a computer to wiggle a flexible mirror in the opposite direction. If the mirror cancels out the atmospheric distortion, then the resulting image is nearly as sharp as one taken from space.

If the telescope has been in orbit since 1990 providing clear visible light images, then it is the Hubble. While James Webb is also in space, it focuses on infrared. Therefore, Hubble is the primary example of a visible/UV space observatory.

If greenhouse gases like water vapor and CO2 are present in the air, then they are very effective at catching infrared photons. If the air catches the photons, then they never reach the telescope on the ground. Therefore, infrared telescopes work best in space or in very dry, high-altitude deserts.

If infrared radiation is essentially heat, then a warm telescope would glow and blind its own sensors. If the JWST wants to see faint heat signatures from distant galaxies, then it must be kept at extremely low temperatures to remain sensitive.

If radio waves have long wavelengths, then they are not easily scattered by gas or dust in the atmosphere. If the atmosphere is transparent to radio waves even when it is cloudy, then there is no need to spend the money to put them in space.

If a telescope is in space and pointed away from the Sun, then the sky is always black because there is no atmosphere to scatter sunlight and create a blue sky. If there is no blue sky to drown out the stars, then the telescope can collect data continuously.

If a telescope must be launched on a rocket, then its diameter cannot be wider than the rocket nose cone. If we want a mirror larger than about 5 meters, then we have to design complex folding mechanisms, which is difficult compared to building a massive mirror on Earth.

If human cities create light pollution, then space is a perfect dark environment. If the atmosphere blocks X-rays, then space is the only place to see them. If the air causes turbulence, then space provides the sharpest view.

If cities use many streetlights, then that light reflects off the atmosphere. If the sky itself becomes bright, then faint stars are no longer visible against the background. This makes ground-based observing near cities nearly impossible.

If light enters a medium like air, then it interacts with atoms and slows down slightly. If space is a vacuum with no atoms, then light travels at its maximum possible speed.

If we combine signals from telescopes spread miles apart, then we can achieve the resolution of a mirror as wide as that distance. If this process uses the interference of waves to create a high-resolution image, then the system is an interferometer.

If ground telescopes are limited by the atmosphere, then their images are always slightly fuzzy. If Hubble is in space, then it can focus light into much smaller, sharper points, making faint, distant objects visible.

If infrared light is absorbed by water vapor, then we need the driest air possible. If we go to a high-altitude desert, then we are above most of the moisture. Therefore, this location provides the best window for infrared light to reach the ground.

If the air inside the dome is warmer than the outside air, then heat waves will shimmer and blur the image. If the astronomer opens the dome early, then the equipment cools down to match the outside temperature. Therefore, achieving thermal equilibrium is necessary for clear viewing.