Absolute Beginners - See Mars and beyond

Absolute Beginners - See Mars and beyond
Mars, Jupiter and Saturn are farther from the Sun than we are, and they're easily seen with the unaided eye. We call them superior planets. Venus and Mercury are the only inferior planets, meaning they are closer to the Sun than we are. All of these can all be bright objects, and have been well known for thousands of years.

The red planet

Mars is perhaps the most glamorous planet. It might harbor life – if not now, maybe in the past. The planet has a starring role in science fiction books, and films such as War of the Worlds. In addition, it's very likely that humans will one day walk on its surface.

Like all the superior planets, Mars is most prominent when it appears at opposition. This is when Mars is directly opposite to the Sun in our sky, and closest to us.

Around the time of opposition, Mars is brighter than any star. It's a fiery red in color, hence its ancient association with the classical god of war. Blood is not involved. The color is due to iron oxide (rust!).

Mars comes to opposition roughly every two years and two months. The next occasions are: December 2, 2022, January 16, 2025 and February 19, 2027. Since Mars will be a bright object for weeks either side of the opposition dates, all is not lost if it's cloudy on the night.

Although it's not usually difficult to find Mars in the sky, it's so small that it's difficult to see its surface features. However, with a small telescope, in good conditions, you might see one of the polar caps and possibly some surface markings.

Around the time of opposition, Mars also seems to do something strange in the sky – it loops backwards against the background stars, before resuming its forward motion, as shown in this multiple-exposure photograph taken by Turkish amateur astronomer Tunç Tezel. Astronomers call this a retrograde loop. The other outer planets also perform such loops, but their loops are much smaller.

Ancient astronomers were puzzled by Mars apparently backing up. However we now know that it's due to the Earth catching up and overtaking Mars as the two planets orbit the Sun. It's like a car on the inner lane of a racetrack passing another on an outer lane.

Giant Jupiter

Jupiter is the biggest planet, 11 times the diameter of the Earth. Swathed in bright clouds, it appears cream-colored. Jupiter comes to opposition about every 13 months, easily outshining the brightest stars. Its next oppositions are on September 26, 2022 and December 7, 2024.

With binoculars or a small telescope, you can see that Jupiter has a slightly squashed outline. The planet spins so quickly on its axis that it bulges at the equator. Dark bands in its clouds can be seen through telescopes, along with a famous feature called the Great Red Spot, a swirling storm cloud larger than the Earth.

Binoculars may reveal Jupiter's four largest moons: Io, Europa, Ganymede and Callisto. These are known as the Galilean moons because they were discovered by Galileo about 400 years ago. They look like tiny points of light changing position from night to night as they orbit Jupiter, sometimes disappearing behind the planet or crossing in front of it.

Serene Saturn

Saturn, the planet with the bright rings, is one of the most beautiful sights in the sky. To the unaided eye, it looks like a bright yellowish star. You might just make out the elongated outline of the rings through binoculars, but a telescope is needed to see them properly.

Around opposition, in good conditions, it's possible with binoculars to see its large moon Titan. It would be a faint point of light fairly close to Saturn.

Distant and slow-moving, Saturn comes to opposition about every two years and two weeks. The next oppositions are on August 14, 2022 and October 7, 2024.

Uranus

I am including Uranus here as a matter of interest, because it is – in the right conditions – a planet that can be seen with the unaided eye. Besides good viewing conditions, you also need to know where it is. It can appear quite bright in binoculars, but Uranus tends to be a telescopic object.

Even experienced observers consult sky charts and guides in order to find Uranus. This is where finding a local astronomy society is helpful, because someone may be able to show you sights such as Uranus or Neptune when they're visible. (Neptune is always a telescopic object.)

The sky at night

There are numerous websites that will tell you about what's up in the night sky. You can do a search to see which one is most helpful for you. I find timeanddate.com useful for all kinds of information. Be sure to enter your own location to get the info you want.



You Should Also Read:
Absolute Beginners - Start Observing
Start Observing - with Binoculars
Heavens-Above - website

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