Observations

Planets Galore

Kirsten Banks is a guide at Sydney Observatory, and loves to talk about space and astronomy. She dreams of becoming a famous Science Communicator like Brian Cox.
In this post, Kirsten discusses the fabulous planets on show in our sky tonight.

This year’s winter sky is arguably one of the best times to come to Sydney Observatory for an action-packed night tour. Not only is August generally one of the driest months, in 2018 astronomers are spoilt for choice with four planets up in the night sky. Looking from West to East, we have a brilliantly bright Evening Star, also known as the fabulous Venus. Looking up towards the middle of the sky is another bright planet with a yellow tinge to it, it is the great Jupiter. Over in the East, we can see a very bright and slightly orange Mars and between Mars and Jupiter is a slightly dimmer Saturn. And right now, as I write this, the Moon is high and bright in the sky, getting bigger and bigger as it approaches its full phase.

I love looking through the telescopes at our extra-terrestrial neighbours. Through our South Dome refractor, I like to show guests Venus and the Moon. The Moon looks absolutely gorgeous through the oldest continually working telescope in Australia. You can see incredible amounts of detail as the shadows dip into deep craters, easily seen through the telescope. Venus also looks somewhat similar to the Moon right now. When we look at Venus we can see what looks like a smaller half-moon. Venus goes through phases just like the Moon does, this is because it’s closer to the Sun than we are on the Earth.

Venus by imaged by the Messenger spacecraft.
Image courtesy of Source: NASA/Johns Hopkins University Applied Physics Laboratory/Carnegie Institution of Washington

 

Moving along to our North Dome, we have a more powerful computerised telescope. I like to use this beast to look at some of our more distant neighbours. First, I like to look at Mars. At first when you look through the telescope, it just looks like a plain old orange circle, especially recently because the entire planet has been covered by a global dust storm that has blocked any features we can usually see at this time. But tonight (late August), the dust storm is calming down and we are able to see the polar ice caps! This is super exciting especially since scientists have recently revealed that there is a lake of liquid water beneath the surface of these ice caps – and we can see them!

Taken in mid-July the NASA/ESA Hubble Space Telescope observed Mars, 13 days before the planet made its closest approach to Earth in 2018.
Image courtesy of NASA, ESA, and STScI

 

Next on my list, we get to some of the more exciting objects – as if there hasn’t been enough excitement already! Next, I like to show the giant of our Solar System, the largest planet, Jupiter. On a clear night you can easily see Jupiter’s striped clouds and sometimes, if you’re lucky, you can even see Jupiter’s massive storm, the Great Red Spot. Around Jupiter, there seems to be three, maybe four bright stars, but these are some of Jupiter’s many moons. Io, Europa, Ganymede, and Calisto – Jupiter’s Galilean Moons. While four moons sounds impressive, Jupiter actually has many more that are hidden from our telescope’s view. Jupiter, now, has 79 confirmed moons orbiting around it. How incredible!

Jupiter and it’s largest moon Ganymede taken by the Cassini spacecraft.
Image courtesy of NASA/JPL/University of Arizona

 

Lastly, I like to have a big finish with arguably the most impressive looking planet, Saturn. It’s a little harder to find with the naked eye, but if you look between bright Jupiter and Mars, you’ll see a yellow-orange dot (that doesn’t twinkle like the stars). Through our telescopes here at Sydney Observatory, we can see everything! You can see a bright yellow ball, which is the planet itself, but then around Saturn you, of course, have the magnificent rings. Saturn’s rings are mostly made up of icy particles, so they are very reflective and easy to see. They really make you go “Wow!”

Saturn imaged on 6 June 2018 by NASA/ESA Hubble Space Telescope (HST).
Image courtesy of NASA, ESA, A. Simon (GSFC) and the OPAL Team, and J. DePasquale (STScI)

So, what are you waiting for? Book your night tour at Sydney Observatory now for your chance to see some beautiful skies and more planets than you can poke a stick at!

One response to “Planets Galore

  • I’ve been watching the procession of the planets across the sky for the last few months during my evening walks. They’ve been putting on an impressive show. I’m looking forward to Venus at its greatest illumination towards the end of September.

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