A storm's a brewin'

It is our third night here at the summit of Mauna Kea and already the nights are starting to drag by. No matter how important the observations you are making, or how amazing the night time sky or day time views, the slow drag of nightly repetition makes it hard to maintain concentration. This evening, though, our alertness has been raised by the weather. Not, you understand the weather at the summit, and certainly not the rain clouds that always lap against the eastern shores of the Big Island; these weather systems are far below us, looking more like an ocean of cloud from the summit. We are more concerned with the high clouds above us - cirrus.

An image taken from the GOES satellite - taken from the Mauna Kea Weather Center - showing the location of cirrus around the Hawaiian islands.

Cirrus clouds are the bane of an observer's existence, because these high ice clouds can cover over the sky, even when you observe from the top of a mountain as high as Mauna Kea. There's nothing you can do about them, but try and wait them out. Tonight, as you can see in the satellite image, we are riding the edge of a giant mass of cirrus to the south of us. Right now the sky is clear, but we saw our data getting scattered by thin wisps an hour ago. It could easily come back soon. To make matters worse, the even thicker set of cirrus to the north is slowly, day by day, forcing its way towards us and there are rumours of a storm coming. Storms are bad, because they cause hot air to rise much higher than is normal, dragging the water laden clouds with them. If they reach us, then the telescope has to close, in case water starts to condense on the telescope mirror.

So we sit, gripped by satellite imagery, high intensity all-sky cameras and even looking out at the night sky with night-vision goggles, hoping to understand what the weather holds for us.

Observing Saturn at the NASA IRTF

Tom Stallard and I, both from the University of Leicester, arrived here at Mauna Kea in Hawaii a couple of days ago and have already spent a full night observing the aurora of Saturn. On our first night we observed for a whole 12 hours which is great since we can observe a complete rotation of Saturn (10 hours), but it can also be somewhat intense, especially with the effects that 14,000 feet of altitude has on mental aptitude. Luckily, we did get some great observations of Saturn and Tom tested out the live streaming of our observations to the web - more on that later.

We are using an instrument on the NASA IRTF called CSHELL, a high resolution spectrograph that allows us to look emission from a molecular ion called H₃⁺, emitting in the auroral region on the planet. These observations will enable us both to determine how the wind is blowing at these high latitudes and what the shape of the aurora is, which in turn will tell us more about the processes responsible for the emission.

All in all, we are going to observe here at the IRTF for 14 nights, scattered throughout the month of April. At the same time we are observing Saturn here from the IRTF, the Cassini spacecraft, which is in orbit about Saturn, will also observe the aurora, both in the infrared (as we are) and the ultraviolet. During this period the Hubble Space Telescope (HST) will also turn its eye towards the aurora Saturn, and as if all this wasn't enough, Tom will head down to Waimea to operate the Keck II telescope for a copule of nights - the world's largest infrared telescope. All in all, this mounts up to a very exciting and unprecedented series of observations - helping us to better understand how the aurora of Saturn is formed and how it evolves over time.

If you would like to look in on us while we observe, then head to: http://connect.le.ac.uk/maunakea - we are observing for the next week between midnight and 6am, Hawaii time. That's 11am and 5pm BST, or noon and 6pm CET.

Tom monitoring the incoming observations of Saturn's aurora. Note the image of Saturn as seen through the guide camera on the right.

Bill keeping an eye on the 1s and the 2s. Each monitor contains information about the status, health and movement of the 3.0 meter telescope.

The 3m NASA IRTF telescope and the shiny inside of the dome. The prime mirror cannot be seen from this angle, but is located in the base of the orange structure - at the top of which is the secondary mirror that reflects the light back down through a hole in the primary mirror to the CSHELL instrument. The height of the orange telescope truss is about 6 metres.