Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:


First extrasolar planets, now extrasolar moons


Credits: ESA 2001. Illustration by Medialab.

ESA is now planning a mission that can detect moons around planets outside our Solar System, those orbiting other stars!

Everyone knows our Moon: lovers stare at it, wolves howl at it, and ESA recently sent SMART-1 to study it. But there are over a hundred other moons in our Solar System, each a world in its own right.
A moon is a natural body that travels around a planet. Moons are a by-product of planetary formation and can range in size from small asteroid-sized bodies of a few kilometres in diameter to several thousand kilometres, larger even than the planets Mercury and Pluto.

Landing on another moon

One such large moon is Titan, the target for ESA’s daring Huygens mission that in 2005 will become the first spacecraft ever to land on a moon of another planet. Titan is slightly bigger than the planet Mercury, and is only called a moon because it orbits the giant planet Saturn rather than the Sun.

Four other large moons can be found around another of our neighbours, Jupiter. These are Io, Europa, Ganymede and Callisto. Europa has captured attention because beneath its icy surface, scientists think that an ocean covers the entire moon. Some scientists have even speculated that microscopic life might be found in that ocean.

Habitable moons?

In 2008, ESA plans to launch its ‘rocky planet’ finder Eddington. By detecting the drop in light seen when a world passes in front of its parent star, Eddington will be capable of discovering planets the size of Jupiter, and also those smaller than Mars.
That means, if our own Solar System is anything to go by, it will be capable of detecting moons similar in size to Titan and the four large moons of Jupiter.

It would be particularly exciting if such combinations of planets and moons were found orbiting a star at Earth’s distance from the Sun. Perhaps then the surfaces of the moons would be warmed to habitable levels.

Orbital dancing

What about moons similar to our own? An equivalent of Earth’s moon would be too small to be detected directly by Eddington, but such a body would affect the way its planet moves and it is that movement which Eddington could detect.

The Earth and the Moon orbit the Sun like ballroom dancers who move around the floor, simultaneously twirling about one another. This means the Earth does not follow a strictly circular path through space, sometimes it will be leading the Moon and sometimes trailing.

This causes variations of up to five minutes from where the Earth would be if it did not possess a moon. By precisely timing when a rocky planet passes in front of its star, Eddington will be able to show if a moon is pulling its planet out of a strictly circular path around the star.

So, how many moons can Eddington expect to find circling planets around other stars? If we make an estimate based on our own Solar System, several thousands will be found — however, no one knows for sure. That’s what makes the quest so exciting!

Monica Talevi | ESA
Further information:

More articles from Physics and Astronomy:

nachricht A new kind of quantum bits in two dimensions
19.03.2018 | Vienna University of Technology

nachricht 'Frequency combs' ID chemicals within the mid-infrared spectral region
16.03.2018 | American Institute of Physics

All articles from Physics and Astronomy >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Tiny implants for cells are functional in vivo

For the first time, an interdisciplinary team from the University of Basel has succeeded in integrating artificial organelles into the cells of live zebrafish embryos. This innovative approach using artificial organelles as cellular implants offers new potential in treating a range of diseases, as the authors report in an article published in Nature Communications.

In the cells of higher organisms, organelles such as the nucleus or mitochondria perform a range of complex functions necessary for life. In the networks of...

Im Focus: Locomotion control with photopigments

Researchers from Göttingen University discover additional function of opsins

Animal photoreceptors capture light with photopigments. Researchers from the University of Göttingen have now discovered that these photopigments fulfill an...

Im Focus: Surveying the Arctic: Tracking down carbon particles

Researchers embark on aerial campaign over Northeast Greenland

On 15 March, the AWI research aeroplane Polar 5 will depart for Greenland. Concentrating on the furthest northeast region of the island, an international team...

Im Focus: Unique Insights into the Antarctic Ice Shelf System

Data collected on ocean-ice interactions in the little-researched regions of the far south

The world’s second-largest ice shelf was the destination for a Polarstern expedition that ended in Punta Arenas, Chile on 14th March 2018. Oceanographers from...

Im Focus: ILA 2018: Laser alternative to hexavalent chromium coating

At the 2018 ILA Berlin Air Show from April 25–29, the Fraunhofer Institute for Laser Technology ILT is showcasing extreme high-speed Laser Material Deposition (EHLA): A video documents how for metal components that are highly loaded, EHLA has already proved itself as an alternative to hard chrome plating, which is now allowed only under special conditions.

When the EU restricted the use of hexavalent chromium compounds to special applications requiring authorization, the move prompted a rethink in the surface...

All Focus news of the innovation-report >>>



Industry & Economy
Event News

Virtual reality conference comes to Reutlingen

19.03.2018 | Event News

Ultrafast Wireless and Chip Design at the DATE Conference in Dresden

16.03.2018 | Event News

International Tinnitus Conference of the Tinnitus Research Initiative in Regensburg

13.03.2018 | Event News

Latest News

A new kind of quantum bits in two dimensions

19.03.2018 | Physics and Astronomy

Scientists have a new way to gauge the growth of nanowires

19.03.2018 | Materials Sciences

Virtual reality conference comes to Reutlingen

19.03.2018 | Event News

Science & Research
Overview of more VideoLinks >>>