USRA works to advance our understanding of the solar system, from its formation, through its evolution, to its current state.
GRAIL Observations Reveal Structure of Lunar Impact Basins
Results from NASA’s Gravity Recovery and Interior Laboratory mission is providing insights into the huge impacts that dominated the early history of Earth’s moon and….
USRA’s Walter Kiefer and Patrick McGovern at the Lunar and Planetary Institute and colleagues examined the origins of the Moon’s giant Orientale impact basin to clarify the effect on the Moon’s geology of the formation of the basin approximately 3.8 billion years ago. In their paper published in Science, the team showed that none of the rings in Orientale basin represent the initial, transient crater. Instead, it appears that in large impacts, like the one that formed Orientale, the surface violently rebounds, obliterating signs of the initial impact.
The powerful impacts that created basins like Orientale played an important role in the early geologic history of the Moon. They were disruptive events that caused substantial fracturing, melting, and shaking of the Moon’s crust. They also blasted out material that fell back to the surface, coating older features that were already there. Analyzing the layering of ejected material helps scientists determine the age of lunar features as they work to unravel the Moon’s complex history.
Unearthing New Clues to the Dinosaur-Killing Impact
Dinosaurs and marine reptiles once dominated the world, but the impact of an asteroid and the series of catastrophic events that followed the impact caused the extinction of all large animals, leading to the rise of mammals and the eventual evolution of mankind. This finding was the result of the work of the International Ocean Discovery Program and International Continental Scientific Drilling Program (IODP-ICDP).
Scientific Drilling Program (IODP-ICDP). Scientists on the expedition drilled an offshore borehole into the site of the asteroid impact, known as the Chicxulub Impact Crater, which is linked, famously, to the K-T or K-Pg mass extinction event. The crater is buried several hundred meters below the surface in the Yucatán region of Mexico.
The international team recovered nearly 14 tons of rock comprising a nearly complete set of rock cores from 506 to 1335 meters (1660 to 4380 feet) below the modern-day sea floor. The team, including USRA’s David Kring of the Lunar and Planetary Institute, studied the rock cores for a first pass at understanding the effects of the impact on life and as a case study of how impacts affect planets.
In a paper published in Science, the scientists show how the basement of Earth’s crust was uplifted over the surface to produce a shattered peak ring in the Chicxulub impact crater that was susceptible to hydrothermal alteration. The team found that the peak-ring is composed of granitic rock that once existed down to 8 to 10 kilometers (5 to 6 miles) beneath the surface. That rock was shattered and shocked, then uplifted above the Earth’s surface before owing outward over the floor of the Gulf of Mexico to form a ring of rock several hundred meters high during the formation of the crater.
The Chicxulub impact event, the environmental calamity it produced, and the paleobiological consequences are among the most captivating topics being discussed in the geologic community.
SOFIA Catches the Shadow of Neptune’s Moon Triton
NASA and DLR's flying telescope, the Stratospheric Observatory for Infrared Astronomy, SOFIA, set out from its home base in Palmdale, California, to Daytona Beach, Florida, in early October to observe Neptune’s moon Triton as it passed in front of a distant star.
As Triton blocked light from the star, it cast a shadow that raced across Earth’s surface at more than 37,000 mph. Catching Triton’s shadow as it races across Earth’s surface while the aircraft is traveling at Mach 0.83 (approximately 636 mph), is no small feat. If a telescope can be positioned in the direct center of the shadow, researchers can make precise measurements of Triton’s atmosphere.
Triton has strong tides because it is close to Neptune, much closer than our moon is to Earth. These powerful tides combined with its strong winds, change the shape of its atmosphere. To measure the overall shape of Triton’s atmosphere, researchers using SOFIA also teamed with more than 30 ground-based telescopes across the Eastern United States and Europe. Most of these telescopes were not located where the center of the shadow fell, but they made simultaneous observations of different areas of Triton’s atmosphere to get a global view of its shape.
The data from ground-based telescopes, combined with that collected by SOFIA’s 100-inch (2.5-meter) on-board telescope and three powerful instruments, helps USRA/NASA researchers understand how Neptune’s gravitational forces influence Triton’s atmosphere, including its temperature, pressure and density.
Soaring Over Pluto’s Majestic Mountains and Icy Plains
On July 14, 2015, NASA’s New Horizons spacecraft made its historic flight through the Pluto system and sent home the first close- up pictures of Pluto and its moons—amazing imagery that inspired many to wonder what a flight over the distant worlds’ icy terrain might be like.
Scientists are still analyzing and uncovering data that New Horizons recorded and sent home after the encounter. On the two-year anniversary of the fly-by, the team is also unveiling a set of detailed, high-quality global maps of Pluto and its largest moon, Charon. USRA’s Paul Schenk of the Lunar and Planetary Institute is a Co-Investigator on the New Horizons mission to Pluto and beyond.
Schenk is an expert in the area of stereo topographic mapping, and led the creation of flyover movies using actual New Horizons data and digital elevation models of Pluto and its largest moon Charon. The movies take the viewer on flyover tours of their incredible landscapes offering spectacular new perspectives of the many unusual features that were discovered and which have reshaped our views of the Pluto system, all from a vantage point even closer than the spacecraft itself.
The topography (or landscape) of planetary surfaces is crucial for understanding their origins and evolutions, along with the benefits and challenges they would raise in exploration. USRA lunar and planetary scientists maintain strong expertise in producing topographic data (digital elevation models) and constructing visualizations of that data (static and dynamic 'fly-overs') focused on specific needs for research and exploration.
Physical processes in the Earth and other planetary bodies are commonly impossible to measure directly and require high-end computer modeling constrained by observations. USRA's Lunar and Planetary Institute maintains the machine capability and expertise for such modeling (finite-element) of processes in the interiors of planets, satellites, and asteroids. Additionally, USRA scientists have significant capabilities in interpretation of Mars mission data and modeling of Mars surface and interior processes.
The Moon, being the planetary body nearest the Earth, is a natural target for scientific exploration. USRA lunar scientists maintain a diverse expertise in lunar geology, including specific expertise in lunar history, impact cratering, remote sensing and volatiles, and resources. Such expertise has been frequently tasked with providing input into NASA planning activities for future robotic and human exploration.
Lunar and Planetary Institute (LPI)
LPI is an intellectual leader in lunar and planetary science. LPI serves as a scientific forum attracting world-class visiting scientists, postdoctoral fellows, students, and resident experts; supports and serves the research community through newsletters, meetings, and other activities; collects and disseminates planetary data while facilitating the community’s access to NASA science; and engages and excites, and educates the public about space science and invests in the development of future generations of explorers.
The research carried out at LPI supports NASA’s efforts to explore the solar system.
Stratospheric Observatory for Infrared Astronomy (SOFIA)
SOFIA is an airborne observatory which conducts observations that are impossible for even the largest and highest ground-based telescopes. SOFIA flies at 38,000 - 45,000 feet to observe in infrared light, which does not reach the Earth's surface. SOFIA is an 80/20 partnership of NASA and the German Aerospace Center (DLR), consisting of an extensively modified Boeing 747SP aircraft carrying a reflecting telescope with a 2.7-meter (106 inch) diameter. The aircraft is based at NASA's Armstrong Flight Research Center in Palmdale, California. NASA’s Ames Research Center in California's Silicon Valley manages SOFIA's science and mission operations, in cooperation with the USRA and the German SOFIA Institute at the University of Stuttgart.
Dr. William Reach, Director