Planets: Sky Watching and Life on Mars
Searching the Sky, Discovery Place’s sky watching feature
Discovery Place Nature
Welcome to Searching the Sky, Discovery Place’s new monthly sky watching and astronomy column. Each month we will take a sneak peek at what will be visible up in the night sky, learn about exciting new discoveries, and make connections to the discipline of astronomy.
This July will be an exceptional time to see planets. Planets are great objects for novice sky watchers to learn to identify, as they are often visible even in light-polluted skies. The planets visible to the naked eye this month are Mercury, Venus, Mars, Jupiter, and Saturn. They are much closer to us than stars other than our own Sun, and thus reflect a bright, steady light back to us here on Earth.
If you don’t own a telescope and would like to get an even better view of these planets, try using binoculars to look at them. You won’t be able to see as many features as you would with a high powered telescope, but you may be able to distinguish some different colors. For example, Mars appears to be a more vivid red through binoculars than when it is observed with just the naked human eye.
Mars will put on a particularly beautiful show in the night sky throughout July and into the fall. This is because Mars will be in a position opposite that of the Sun in our sky. Planets in opposition appear slightly brighter than when they are in other positions because they reflect more light from the Sun.
In addition to an increase in brightness due to its position opposite of the Sun, Mars will also appear bigger and brighter in our sky as it moves closer to Earth during its elliptical orbit around the Sun. On July 31, Mars will reach the point closest to the Earth in its path and pass within 35.8 million miles of us. Mars won’t make another close approach until 2020, so catch it while you can! Jupiter, usually the second brightest planet in the sky after Venus, will not be as bright as Mars this July, but will still be relatively bright and visible. You can catch Jupiter, Mars, and Saturn in the southern night sky throughout the month. Venus will also be visible in the early evening sky above the setting Sun.
NASA also just announced that they discovered organic material on Mars. Contrary to popular belief, that does not mean that NASA’s Curiosity rover has necessarily found evidence of material left by living things, but does mean that Curiosity has identified organic compounds: compounds that contain carbon and hydrogen molecules. These molecules could come from life that once existed on Mars or from a nonliving source. As far as we know, organic compounds act as the building blocks of life, and are necessary to the existence of life, so the existence of these organic compounds, the methane recently detected in the atmosphere of Mars, and the indications that Mars may have had liquid water on its surface in the past are all pieces of evidence that point towards the possibility of life on Mars.
NASA’s InSight mission, which will study seismic activity on Mars, recently left Earth and is scheduled to arrive at Mars in November. NASA also hopes to land another rover on Mars in 2020, and is currently planning on sending humans to Mars in the 2030s. Hopefully we’ll continue to learn more about the possibility of life on Mars as NASA devotes more resources to the study of the Red Planet.
Caroline O’Neill is a Discovery Place Nature educator and astronomy enthusiast. Continue checking Searching the Sky each month for updates on what you can see in the sky above you and new discoveries in astronomy.