Planetary Science Sub-committee Meeting

8 April 2010

http://www.lpi.usra.edu/vexag/ Completed:

Upcoming:

8 April 2010 PSS Meeting: VEXAG Status Limaye - 2 • Express is operating normally. ESA has approved extension through end of 2012. Orbit change from 24 hour period to 12 hour being planned which will enable spacecraft operations through ~ 2015.

• JAXA’s (Venus Climate Orbiter) spacecraft is now at the launch site. Launch window opens May 18, 2010. Expected to arrive at Venus in December 2010 and observe Venus from a 172 degree eccentric, 30 hour orbit.

8 April 2010 PSS Meeting: VEXAG Status Limaye - 3 Future International Venus Exploration Efforts

• European Venus Explorer, a balloon mission undergoing preliminary studies in Europe for a proposal to be developed for the next round of Program in ~ 2011.

• D is mission concept (Balloons, landers, orbiter) being studied in Russia for potential launch after 2016.

Informal overtures being made to ISRO to promote potential interest in missions to Venus. A mission to Mars in 2013-2015 is under consideration by ISRO.

ISRO appears interested in considering Venus as a future target

8 April 2010 PSS Meeting: VEXAG Status Limaye - 4 Status

No missions to Venus have been selected so far for implementation in NASA’s Discovery, despite proposals deemed selectable The rich science questions about Venus, spanning from surface, interior, atmosphere, and ionosphere, will require many missions for answers. No large, multi-element mission to Venus is likely before 2020. Technology development, including precursor missions, is needed to enable many key missions for Venus.

SAGE is one of three New Frontiers missions developing Concept Study Reports (due January 2011) A number of concepts under development for the Discovery Program

8 April 2010 PSS Meeting: VEXAG Status Limaye - 5 What’s left to be observed?

• Atmospheric Superrotation (Upper Thermosphere and below Clouds) – Still do not have good estimates of meridional angular momentum by eddy and mean circulation – No measurements of the dynamical thermal tide (winds) and the vertical momentum transport by the thermal tides. – Coupling with the surface – exchange of angular momentum with the surface • Clouds – What is the UV absorber? • Surface and Geology Is it active now? How are the interior, surface, and atmosphere linked? How did Venus diverge from Earth? • Interior How did Venus evolve into a stagnant lid planet? How do stagnant lid planets operate? • Evolution – Noble gas abundances – D/H ration variations above/below clouds

8 April 2010 PSS Meeting: VEXAG Status Limaye - 6 Venus Community: In danger of becoming extinct? • Looking for # proposals submitted/funded • The problem may not only be “compelling” proposals but also with cognizant reviewers (dwindling Venus community?) • No NASA missions to Venus after – difficult to attract and support graduate students • PS budgets too small for to do much “science” with . • Community excited about the opportunity to participate in VCO

8 April 2010 PSS Meeting: VEXAG Status Limaye - 7 Why Venus…

• Relevance of Venus in understanding the evolution of terrestrial planets not just in our solar system – Relevance to Earth’s future climate

• We need to understand Venus Climate evolution to boost confidence in estimates of future climates on Earth • Many terrestrial exoplanets may be more like Venus than Earth

8 April 2010 PSS Meeting: VEXAG Status Limaye - 8 Why Venus? Why now? Venus, Earth and Climate Change • Venus is an extreme case of global warming. – Provides an active example of runaway greenhouse warming and the role of cloud-climate feedback • Venus provides our closest (and only) planetary analog for many important terrestrial climate processes. – Ozone loss on the Earth was discovered due to the study of Venus upper atmospheric chemistry • Simulating the extreme climate of Venus can: – help to validate terrestrial general circulation models and increase understanding of nonlinear climate feedbacks – expose limitations of current climate models. • Many scientific problems of common interest to both Venus and Earth climate studies: – Aerosol microphysics and radiative properties, cloud morphologies and climate forcings, mesoscale and vortex dynamics, atmospheric responses to short and long term solar forcing – Volcano-climate interactions – Atmospheric angular momentum and exchange with solid planet – Venus dynamical phenomena compared Earth stratospheric oscillations

8 April 2010 PSS Meeting: VEXAG Status Limaye - 9 Upcoming Events

• ESA/Venus Express workshop in Aussois, france in late June 2010 to consider Venus Express results and discussion of Venus 3 Book

• VEXAG Workshop “Venus Atmosphere: from Surface to Thermosphere”, 30 August – 2 September 2010 in Madison, Wisconsin

• Special Issue of Icarus planned for papers from both of these workshops (due date is October 31, 2010).

• PSD Technology Committee will also meet on 31 Aug/1 September in Madison concurrently with the VEXAG Workshop.

8 April 2010 PSS Meeting: VEXAG Status Limaye - 10 What’s New on Venus?

• It may be “active” !!! • Paper being published in Science today (Smrekar et al.) based on Venus Express observations

8 April 2010 PSS Meeting: VEXAG Status Limaye - 11 VEXAG Proposal: Long-term communications capability with an orbiter

 A long term communications capability in orbit would enable more robust balloon and lander missions which will occur in the future.  The same capability will also enable mutual radio occultations with other orbiters to arrive at Venus to provide data on the Venus atmosphere.  Options exist to create such an asset:  Collaborate other space agencies to create an orbiting communications capability by contributing a transceiver  Provide credit and/or equipment to Venus Discovery or New Frontiers orbiter missions for providing long-term communications capability

8 April 2010 PSS Meeting: VEXAG Status Limaye - 12