Glossary of Astronomy Terms. The universe is a large place full of wondrous and unimaginable things. The amateur astronomy hobby contains words, labels, and technical terms that may seem be a little confusing for both beginners and the more experienced hobbyists. This glossary of astronomy terms contains definitions for some of the most common words used in astronomy, cosmology, astrophysics, and space exploration. You may click on any yellow highlighted word to jump directly to the definition for that astronomy word. You can also click on any letter of the alphabet below to jump directly to that section in the astronomy glossary listing.
The lowest energy transfer to Mars is a Hohmann transfer orbit; a mission to Mars using Hohmann transfer involves an approximately 9 month travel time from Earth to Mars, about five hundred days at Mars to wait for the transfer window to Earth, and a Hohmann transfer of about 9 months to return to Earth.
When you consider the fact that Mars is only 55 million km away, and the spacecraft are travelling in excess of 20,000 km/hour, you would expect the spacecraft to make the journey in about 115 days, but it takes much longer.ore fuel, shorter travel time. The History of Going to Mars. The first spacecraft ever to make the journey from Earth to Mars was NASAâs Mariner 4, which launched on November 28, 1964 and arrived at Mars July 14, 1965, successfully taking a series of 21 photographs. Mariner 4âs total flight time was 228 days.