Observing Venus from ground
Science & Exploration

Ground-based observatories join forces with Venus Express

23/05/2007 1209 views 0 likes
ESA / Science & Exploration / Space Science / Venus Express

Data from Venus Express, which has been revealing new and crucial details about our closest planetary neighbour, will now be augmented by synoptic data from a coordinated ground-based observation campaign.

This campaign will contribute to the growing body of information on the nature of Venus’s atmosphere and will help put the spacecraft’s observations into a broader context.

Between 23 May and 9 June, scientists working at a dozen telescopes and observatories spread all over the world will examine Venus from the ground and perform measurements, some of which are not feasible for Venus Express.

Venus Express
Venus Express

By applying different techniques and performing measurements at wavelengths that are not within the capabilities of the spacecraft, scientists intend to complement the existing dataset and obtain simultaneous measurements and cross-validation of the spacecraft’s observations.

Thus the ground-based observations - radio, submillimetre, infrared and visible - are very useful for interpretation of Venus Express results.

The main focus of the ground-based observations is on measurements of the atmosphere above Venus’ cloud tops. This will complement Venus Express’ capability to study the cloud layer in high detail and the lower atmospheric altitudes, down to the surface.

Spectroscopy at visible, infrared and submillimetre wavelengths from ground-based observatories will enable direct measurements of the wind and unearth fresh data about the mesosphere and the thermosphere, two atmospheric layers situated above Venus’ cloud deck.

This directly complements Venus Express, which determines wind characteristics by tracking motions of the clouds and studies the distribution of gaseous species and temperatures in Venus’ upper atmosphere.

Previous examples demonstrate the importance of connecting space-borne observations with the synoptic coverage from ground.

Following on Venus Express’ investigations, the ground-based observations will perform studies of Venus’ oxygen airglow emission – a phenomenon detectable on the night-side that makes the planet glow – and study the composition of the mesosphere and the deep atmosphere.

The timeframe of the ground-based campaign, which extends from 23 May to 9 June, was chosen for different reasons. The most important reason is the fact that Venus is close to its maximum elongation, that is its maximum angular distance from the Sun as seen from Earth, during this period. This is a favourable position for observations of both its day and night sides from Earth.

The time window also encompasses the Venus flyby of NASA’s Messenger on 6 June at 1:10 CEST, en route to its final destination, Mercury. For one day, Messenger’s observations of Venus will also complement those from Venus Express and ground.

Who is involved?

The telescopes involved in the ground - based campaign
The telescopes involved in the ground - based campaign

The telescopes involved in the Venus ground-based observation campaign are:

 

  • CFHT: Canada-France-Hawaii Telescope, Hawaii
  • OHP: Observatoire de Haute Provence, France
  • VLT: Very large Telescope, Chile
  • Observatoire du Pic du Midi, Telescope Bernard Lyot (TBL), France
  • IRAM: Institut de Radio-Astronomie Millimetrique, Spain
  • IRAM PdB: Institut de Radio-Astronomie Millimetrique: antennae at Plateau de Bures, France
  • JCMT: James Clerk Maxwell Telescope, Hawaii
  • Nobeyama: Radio Observatory, Japan
  • HHT: Heinrich Hertz Submillimeter Telescope Observatory, Arizona, USA
  • Kitt Peak National Observatory, Arizona, USA
  • IRTF: Infrared facility, Hawaii
  • AAT: Anglo-Australian Telescope, Siding Spring Mountain in north-western New South Wales, Australia
  • Keck telescope (Hawaii)

Ground-based campaigns for previous missions

ESO's Very Large Telescope (VLT) at Cerro Paranal
ESO's Very Large Telescope (VLT) at Cerro Paranal

“Previous examples demonstrate the importance of connecting space-borne observations with the synoptic coverage provided by continued ground-based programmes,” said Emmanuel Lellouch, Venus Express Supporting Investigator and coordinator of the ground-based observation campaign.

One of the recent ground-based observation campaigns in support of a scientific mission was conducted during the Huygens probe’s descent and landing on Titan on 14 January 2005. As Huygens parachuted to the surface of Titan, a battery of radio and optical telescopes around the world were watching and listening.

The observations brought in new information on the atmosphere and surface properties of Saturn’s largest moon. They also provided information about the probe’s drift in the winds and thus helped to reconstruct the descent trajectory and the coordinates of the landing site.

Other supporting ground-based observations were successfully performed for other scientific missions such as ESA’s SMART-1 which flew to the Moon and NASA’s Deep Impact which flew to comet 9P/Tempel 1.

There are also a large number of amateur astronomers watching Venus regularly, obtaining excellent images to complement data from observatories. During the current campaign, Venus is particularly bright and thus easily observable, even with small telescopes, for amateurs’ viewing pleasure.

For more information

Emmanuel Lellouch, VEX Supporting investigator, Observatoire de Paris, France
Email: Emmanuel.Lellouch @ obspm.fr

Olivier Witasse, ESA Venus Express Deputy Project Scientist
Email: Olivier.Witasse @ esa.int

Related Links

Venus’ fickle atmosphere (colour image)
Agency

500 days at Venus, and the surprises keep coming

03/09/2007 1486 views 0 likes
Open item
MESSENGER bids farewell to Venus
Science & Exploration

Venusian rendezvous results: chapter one

19/07/2007 1323 views 0 likes
Open item
Venus Express
Science & Exploration

Venus Express and MESSENGER to look at Venus in tandem

04/06/2007 1816 views 1 likes
Open item
Observing Venus from ground
Science & Exploration

Ground-based observatories join forces with Venus Express

23/05/2007 1209 views 0 likes
Open item
The Venus Express spacecraft
Science & Exploration

Join ESA on the Venus observation campaign

17/03/2006 776 views 0 likes
Open item
Zoom-in on Venus’ oxygen airglow
Science & Exploration

One year at Venus, and going strong

11/04/2007 1803 views 0 likes
Open item
Multiple views of Venus’ clouds
Science & Exploration

Tracking alien turbulences with Venus Express

03/04/2007 1668 views 1 likes
Open item
Temperature maps of Venus’ surface
Science & Exploration

Hot stuff on Venus! Venus Express sees right down to the he…

14/12/2006 3148 views 4 likes
Open item
'Thin' cloud layer close to Venus' South pole
Science & Exploration

Happy birthday, Venus Express!

09/11/2006 1479 views 0 likes
Open item
Radiation from below the Venusian cloud deck
Science & Exploration

Complex meteorology at Venus

13/10/2006 1997 views 4 likes
Open item
Global dynamics of Venus northern hemisphere
Science & Exploration

Flying over the cloudy world – science updates from Venus E…

12/07/2006 5779 views 5 likes
Open item
Double vortex at Venus South pole
Science & Exploration

Double vortex at Venus South Pole unveiled!

27/06/2006 11181 views 7 likes
Open item
Artist's impression of Venus Express
Science & Exploration

Venus Express has reached final orbit

09/05/2006 2724 views 2 likes
Open item
Dark Vortex over South Pole of Venus
Science & Exploration

Unexpected detail in first-ever Venus south pole images

13/04/2006 4060 views 0 likes
Open item

Related Links