On a clear night, when looking up at the heavens, it may be tempting to imagine that those little lights in the night sky are just stars, planets or aircraft, says Dr Simon Keogh, in the latest of a series of blogs on satellites. Dr Keogh leads the Met Office Satellite Data Products and Systems group

However, he adds, some of these lights in the sky are actually satellites. There are rather a lot of them up there and they’re not only there for weather forecasting. In the early morning or evening you can sometimes spot polar-orbiting satellites drifting slowly overhead. They appear as a small speck of light that moves from horizon to horizon over a period of a few minutes. The light you can see is actually sunlight being reflected off the large solar panels that the satellite relies upon for power. This light is sometimes referred to as a “flare”.

Photo (courtesy of NOAA) of the International Space Station tracking across the sky at night.

The International Space Station (ISS), Tim Peake’s new and temporary home, is perhaps the most well-known satellite, orbiting the Earth at an altitude of around 435km (270 miles). The flare from the huge solar panels on the ISS make it reasonably easy to spot in the night sky.

Interestingly, in recent times the ISS has even been contributing valuable information on ocean surface winds from the RapidScat instrument, which is great for marine weather forecasting applications. We very much hope that RapidScat continues to work well and that it never needs attention from Tim or the other ISS astronauts.

We take these satellites for granted, but we shouldn’t. Thanks to weather satellites we have accurate forecasts and timely warnings to help us prepare for the worst the weather can throw at us. Without weather satellites, we’d be living in a world where the next flood, the next heat wave and the next storm surge would come without warning with potentially disastrous consequences.

Fortunately, the Met Office is an active participant in the design of many future satellite missions so we look forward to having weather satellites around for a long time to come.

Working with colleagues internationally, we make sure that the needs of the UK for satellite data are represented on a global stage. If you want to find out more about weather satellites and what we do with them in the Met Office then please visit http://www.metoffice.gov.uk/learning/first-steps/observations/satellites

The International Space Station is relatively easy to spot as it is the second brightest object in the night sky (after the moon), and orbits the earth around 16 times each day. Picture courtesy: NASA.

To see the ISS for yourself please visit the following website for details: http://spotthestation.nasa.gov

Dr Simon Keogh leads the Met Office Satellite Data Products and Systems group. He is a member of a United Nations WMO expert team on Satellite Utilisation and Products and is the UK delegate to EUMETSAT’s Operations Working Group.

Link to my page on the research pages:

http://www.metoffice.gov.uk/research/people/simon-j-keogh