Dwayne Brown / JoAnna Wendel
NASA Headquarters, Washington
Jet Propulsion Laboratory, Pasadena, Calif.
While headlines routinely report on “close shaves” and “near-misses” when near-Earth objects (NEOs) such as asteroids or comets pass relatively close to Earth, the real work of preparing for the possibility of a NEO impact with Earth goes on mostly out of the public eye.
For more than 20 years, NASA and its international partners have been scanning the skies for NEOs, which are asteroids and comets that orbit the Sun and come within 30 million miles (50 million kilometers) of Earth’s orbit. International groups, such as NASA’s Planetary Defense Coordination Office (PDCO), the European Space Agency’s Space Situational Awareness-NEO Segment and the International Asteroid Warning Network (IAWN) have made better communication of the hazards posed by NEOs a top priority.
April 25, 2019
MEDIA ADVISORY M19-034
Media are invited to hear experts from around the world discuss the latest research on near-Earth objects (NEOs) at the International Academy of Astronautics’ 2019 Planetary Defense Conference, Monday, April 29 through Friday, May 3 at The Hotel at the University of Maryland.
NEOs include asteroids and comets that orbit our Sun and come within 30 million miles of Earth’s orbit, where some may pose an impact hazard to our planet. NASA experts will talk about the agency’s first mission to demonstrate a technique to change the motion of an asteroid in space and other aspects of the nation’s planetary defense program.
European Space Agency, Noordwijk, Netherlands
M. Ramy El-Maarry
University of Colorado
ESA Rosetta project scientist
NOTE: Make sure you check 0ut the accompanying Space Photo Exploration page for Comet 67P/Churyumov-Gerasimenko
The European Space Agency’s Rosetta Comet mission has chosen five likely landing sites for its Philae’s lander on comet 67P/Churyumov-Gerasimenko. The lander is scheduled to descend down to the comet’s nucleus in November.
According to a press release by NASA’s Jet Propulsion Laboratory:
Rosetta is an international mission headed up by the ESA with support from NASA, and will be the first ever attempt to land on a comet.
Rosetta is an international mission headed up by the ESA with support from NASA, including providing instruments.
Due to the distance from Earth and the orbiter and lander creates uncertainties in navigating the orbiter close to the comet, the only way possible to pick a landing site in terms of an ellipse, which will cover up to six-tenths of a square mile (or one square kilometer) where the Philae lander might land.
“This is the first time landing sites on a comet have been considered,” said Stephan Ulamec, Philae Lander Manager at the German Aerospace Center, Cologne, Germany in a press release.
Will the lander be able to maintain regular communications with Rosetta?
Is there sufficient illumination for scientific operations and enough sunlight to recharge the lander’s batteries beyond its initial 64-hour lifetime without causing overheating?
The team reduced the number of landing sites from 10 to five, and gave them letters that have no special meanings.
“The process of selecting a landing site is extremely complex and dynamic; as we get closer to the comet, we will see more and more details, which will influence the final decision on where and when we can land,” said Fred Jansen, Rosetta’s mission manager from the European Space Agency’s Science and Technology Centre in Noordwijk, The Netherlands, in the same press release.
During the time the team is preparing their analysis, Rosetta will move to 31 miles (50 kilometers) of the comet allowing more detailed study of the five landing sites.
The ESA Rosetta team plans to land the Philae lander sometime around mid-November when the comet will be about 280 million miles (450 million Kilometers). This means the comet will be three times the distance than the Earth is to the Sun (280 million miles also equals 3 astronomical units, where an astronomical unit is 93 million miles, or the distance between the Sun and the Earth).
At 3 AU, there should be little to no activity on the comet that would jeopardize the landing of the Philae lander on the comet’s surface, and just before the comet becomes active.
Launched in March 2004, Rosetta was reactivated in January 2014 after a record 957 days in hibernation. Composed of an orbiter and lander, Rosetta’s objectives since arriving at comet 67P/Churyumov-Gerasimenko earlier this month are to study the celestial object up close in unprecedented detail, prepare for landing a probe on the comet’s nucleus in November, and track its changes through 2015, as it sweeps past the sun.
Cosmologists consider comets as time capsules containing materials left over from building of the Solar System 3.4 billion years ago. Rosetta’s lander will obtain the very first images taken from a comet’s primordial composition by drilling into the surface.
According to the press release:
Rosetta is an ESA mission with contributions from its member states and NASA. Rosetta’s Philae lander is provided by a consortium led by the German Aerospace Center, Cologne; Max Planck Institute for Solar System Research, Gottingen; French National Space Agency, Paris; and the Italian Space Agency, Rome. NASA’s Jet Propulsion Laboratory in Pasadena, California, a division of the California Institute of Technology, manages the U.S. participation in the Rosetta mission for NASA’s Science Mission Directorate in Washington.
For Specifications on: 67P/Churyumov-Gerasimenko