Journey to a Red Planet

Young Astronomers Blog, Volume 28, Number 16.

From time to time if you look up into the night sky, you might see an orangish/reddish object. This most likely is the planet Mars. As well-known as Mars is, it is not a great sight through a small telescope. A telescope with a relatively large aperture is required to see surface details including the white polar caps. However, every two years or so, Mars does appear as a bright reddish object in the night sky.

Mars takes around two years to orbit the Sun. Because of the Earth’s one-year orbit, it approaches near to the Earth only once every 26 months. Planets farther from the Sun than the Earth reach their closest approach around the same time as their opposition, which is when the planet is exactly opposite the Earth from the Sun and you can draw a straight line from the Sun through the Earth to the planet.

Mars has a slightly elongated orbit, so some oppositions (and closest approach) are nearer to the Earth than others. The last opposition in 2018, at 35.8 million miles, was the closest since 2003 when it was 33.9 million miles away. Mars will reach another opposition on October 13, 2020, and its closest approach to the Earth of 38.6 million miles will take place a week earlier on October 6, 2020. During this time, Mars will reach a magnitude of -2.6 and will be visible most of the night below Pegasus in the constellation Pisces. By the way, on the night of October 2, Mars will appear in the vicinity of a full Moon.

Italian astronomer Giovanni Schiaparelli and American Percival Lowell were the first to extensively study the surface of Mars. They both created detailed maps of the planet and thought they had found channels and canals crossing the surface. Lowell, in fact, became convinced that these canals were proof of intelligent life on the planet Mars. He was wrong. The channels and canals turned out to be optical illusions.

Since the dawn of the space age, many spacecraft, both orbiters and landers, have visited Mars.  Mariner 4 flew by Mars in 1964 and sent back 21 grainy black and white images. Mariner 9 went into orbit around Mars in 1971 and found the huge mountain Olympus Mons and the deep canyon Valles Marineris. Viking 1 and 2 landed on Mars in 1976 and along with two Viking orbiters sent back tremendous views of the Martian surface. Over the years, other orbiters including the Mars Global Surveyor, Mars Odyssey, Mars Express, Mars Reconnaissance Orbiter, and MAVEN have circled the planet providing a continuous view of the Martian surface. Rovers, including Sojourner, Spirt, and Opportunity have travelled across the Martian terrane. In 2012, the Mars Science Laboratory (Curiosity), landed in the Gale Crater near a three-mile-high mountain (Mt. Sharp). It has been exploring the crater and slopes of Mt. Sharp ever since.

Successfully getting to Mars isn’t a sure thing. Missions such as the Mars Observer, Mars Climate Orbiter, and the Mars Polar Lander have failed in some way. Landing on Mars is possibly the most difficult task. Spacecraft are moving at thousands of miles per hour as they approach the red planet. They have only a few minutes to slow down and land safely. The first few spacecraft to land on Mars used rockets to break their fall. Later, a few rovers bounced to the surface using air bags to cushion the fall. Curiosity performed the most complex landing – one which NASA described as the “seven minutes of terror.”

This summer, another rover will begin its journey toward the red planet. The Mars 2020 rover, now known as Perseverance, is scheduled to launch in late July, although the launch window is open until August 15, 2020.

Perseverance will land on Mars within the Jezero crater on February 18, 2021. Looking much like Curiosity, Perseverance will carry several primary instruments along with the first Martian helicopter named Ingenuity. Its landing will be like that of Curiosity, another seven minutes of terror.

So, mark your calendars as the next phase of Martian exploration begins.

By the way, Perseverance will be joined by two other Martian missions this year. The UAE/Emirates Mars Mission launched  The Hope Probe (an orbiter) and China has sent Tianwen-1 (an orbiter, lander, and rover) toward Mars. Another mission by the European Space Agency (EAS) and Russian Space Agency (Roscosmos) was originally scheduled for this year but has been pushed back to 2022.

Selected Sources and Further Reading

“Mars.” Solar System Exploration, NASA Science. (accessed April 12, 2020). https://solarsystem.nasa.gov/planets/mars/overview/

“Mars Exploration Program.” NASA. (accessed May 2, 2020). https://mars.nasa.gov/

Bruce McClure. “The cycle of close and far Martian oppositions.” EarthSky. July 30, 2018. https://earthsky.org/sky-archive/close-and-far-martian-oppositions

Fraser Cain. “What’s The Distance to Mars?” Universe Today. December 5, 2013. https://www.universetoday.com/14824/distance-from-earth-to-mars/

“Mars in our Night Sky.” Mars Exploration Program, NASA Science. (accessed May 2, 2020). https://mars.nasa.gov/all-about-mars/night-sky/opposition/

Dominic Ford (Editor). “Mars.” In-The-Sky.org. (accessed May 2, 2020). https://in-the-sky.org/article.php?term=Mars

“The Mars Rovers.” Space Place, NASA Science. https://spaceplace.nasa.gov/mars-rovers/en/

“Opportunity: NASA Rover Completes Mars Mission.” NASA/JPL-Caltech. February 13, 2019. https://www.jpl.nasa.gov/video/details.php?id=1570

“Challenges of Getting to Mars: Curiosity’s Seven Minutes of Terror.” NASA Mars Exploration Program, NASA Science. June 22, 2012. https://mars.nasa.gov/resources/20049/challenges-of-getting-to-mars-curiositys-seven-minutes-of-terror/?site=msl

“Mars Curiosity Rover.” Mars Exploration Program, NASA Science. (accessed May 2, 2020). https://mars.nasa.gov/msl/home/

“Mars 2020 Mission Perseverance Rover.” NASA Science. (accessed May 2, 2020). https://mars.nasa.gov/mars2020/

“Watch Online – Upcoming Livesteam, NASA science Live: Perseverance Mars Rover & the Search for Ancient Life.” Mars  2020 Mission Perseverance Rover, NASA Science. (accessed July 11, 2020). https://mars.nasa.gov/mars2020/timeline/launch/watch-online/

Jamie Carter. “Mars Alert: Why Three Spacecraft Must Leave For the Red Planet Within Weeks Or Miss Their Chance.” Forbes. July 8, 2020. https://www.forbes.com/sites/jamiecartereurope/2020/07/08/mars-alert-why-three-spacecraft-must-leave-for-the-red-planet-within-days-or-miss-their-chance/#26e385445f93

Brian Ventrudo. “The Man of Mars – Percival Lowell and the Invention of the Red Planet.” Cosmic Pursuits. March 26, 2018. https://cosmicpursuits.com/2043/the-man-of-mars-percival-lowell-and-the-invention-of-the-red-planet/