Herschel and Planck: the ESA looks for the early years of the Universe

Just over 3 hours from the time I write this, the European Space Agency will launch two satellites. Both will study the early stages of the universe. Watch itlive at this link, or follow them on Twitter.

What will they do?

  • Herschel will carry an infrared telescope. That means it won’t capture visual-spectrum images like Hubble has. What it will catch, in frequencies and detail never before achieved, is information about early star and planet formation. Because its sensitivity is so high, and because radiated heat is infrared, the satellite has an elaborate cryogenic system to keep it super-cool.
  • Planck won’t take visual images either: it’ll measure, in great detail, the Cosmic Microwave Background radiation (that is, the radiation left over from just after the Big Bang).

Each will do lots of other things, too. Read the links.

Ariane 5 enclosing Herschel and Planck

GOCE launch approved for today: getting the details on gravity

The Russian State Commission has given the green light for the launch, in just a couple of hours, of a sophisticated satellite to investigate the Earth’s gravitational field. The Gravity field and steady-state Ocean Circulation Explorer (GOCE), a European Space Agency (ESA) project is to be launched today at 15:21 CET.

GOCE data will let us accurately measure sea-levels and ocean circulation, which are affected by climate change. So what? you say.

Well, we all know the Earth (like all objects with mass) results in gravity. However, the effect of gravity depends on the amounts of mass involved and on the distance away from the mass. Although it’s usually sufficient to think of the Earth as a big round ball, it is in fact neither a perfect sphere on macro (a big sphere in space) nor micro (hills and valleys and seabeds) levels. Neither is its mass distributed uniformly around the globe nor through the layers of its interior. Thus, gravity varies around the surface of the globe.

If we want to get down to the nitty-gritty of the dynamic processes taking place on Earth’s surface and in its interior – sea level changes due to climate change, seismic activity, etc – we need the nitty-gritty detail of how gravity varies around the world. An accurate gravity map – called a geoid – thus becomes an important thing to understand.

Check here for the main GOCE site.

The GOCE Ion Propulsion Assembly being prepared for testing in QinetiQ's thermal vacuum chamber