Once you get to know your way around the sky and spend a lot of time under the stars you can start seeing amazing things. These are some of the things that I have seen in my two plus years of being an Astronomy guide, spending almost every night under the stars in a dark sky reserve.
Firstly, I want to talk about the Galilean moons of Jupiter casting shadows on Jupiter.
With a big telescope and the right timing you can see the shadow of one of the 4 Galilean moons. The shadow on Jupiter is a little black dot on the cloud tops. Sometimes you can even see two moons casting shadows on Jupiter! The shadows take about two hours to cross the disk of Jupiter so you do need to time it right and have your telescope in sharp focus. It is amazing to see these moons causing eclipses on another planet.
Another predictable event that you can see is an occultation of Saturn by the Moon.
This happens when the Moon covers up Saturn. It is very exciting to watch the Moon getting closer and its bright moonlight washing out the dimmer Saturn. Until in a matter of a few minutes the Moon completely covers up Saturn. Then, once the Moon has moved past again, Saturn is revealed on the other side. Watching Saturn reemerge from the other side of the Moon that is dark as is covered in shadow was amazing, as Saturn was very bright when it reemerged.
Credit Holly McClelland
Weather balloons UFOs
Often weather balloons are labeled as UFOs since they can be very bright and stay mostly in one place. In 2017, NASA launched a weather balloon from Wanaka and it could be seen across all Canterbury. In Tekapo we saw this bright point in the sky when we were setting up the telescopes at sunset, so immediately turned the telescopes around to have a closer look. And you could clearly see the balloon with the payload hanging below. We even got a photo of it (see the above image). As the balloon was only lit up by the sunlight, as the Earth turned further away from the Sun, the weather balloon became more and more ghost like until it disappeared from view. Later on in the night, the balloon popped and we saw its remains burn up through the atmosphere. It looked like a bright meteor moving vertically down behind the mountains. Very cool to see and have not seen anything like it since.
The ISS and other spacecraft
One night the International Space Station (ISS) was predicted to fly over head so I went outside to watch it. It flew overhead nice and bright but then I noticed a dimmer satellite that appeared to follow the ISS across the sky, it had the same path and speed as the ISS it was just lagging behind a bit. After some jokes about aliens invading the ISS and some googling I found out the ISS was about to dock with a resupply capsule, SpaceX’s Dragon cargo craft. 90 minutes later when the ISS orbited back around we could see it had already docked with the resupply mission. Very cool to see.
Everyone hopes to see a meteor or ‘shooting star’ when they go stargazing. The brightest meteor I have seen was so powerful that it lit up the entire sky, reaching fireball status. Firstly, I thought someone has turned the headlights on a car on, it was that bright and I have only seen one like that in over two years of being an Astronomy guide. All the guests on my tour were facing the wrong way and they started wondering why it suddenly got so bright. It just goes to show that you need to be looking in the direction of it and be lucky to see a fireball.
Credit: Joseph Pooley
And most recently, I got to see the gas cloud from a SpaceX rocket launch. Just after 10 pm on the 25th June in New Zealand we saw a glowing cloud on the north west horizon, it looked very similar to the Magellanic clouds, a gassy looking cloud lit from within. At first we did not know what we were looking at until one of our guides said that a SpaceX Falcon heavy rocket launch a few hours ago. Our photographer that night Joseph Pooley rushed off with his camera to get a few snaps before the cloud disappeared in a matter of minutes.
The sky is often full of surprises and it is incredible to know its secrets. And sometimes, with some luck, planning and good weather, you can see unique events.