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By NASA
5 min read
Preparations for Next Moonwalk Simulations Underway (and Underwater)
Typically, asteroids — like the one depicted in this artist’s concept — originate from the main asteroid belt between the orbits of Mars and Jupiter, but a small population of near-Earth objects may also come from the Moon’s surface after being ejected into space by an impact.NASA/JPL-Caltech The near-Earth object was likely ejected into space after an impact thousands of years ago. Now it could contribute new insights to asteroid and lunar science.
The small near-Earth object 2024 PT5 captured the world’s attention last year after a NASA-funded telescope discovered it lingering close to, but never orbiting, our planet for several months. The asteroid, which is about 33 feet (10 meters) wide, does not pose a hazard to Earth, but its orbit around the Sun closely matches that of our planet, hinting that it may have originated nearby.
As described in a study published Jan. 14 in the Astrophysical Journal Letters, researchers have collected further evidence of 2024 PT5 being of local origin: It appears to be composed of rock broken off from the Moon’s surface and ejected into space after a large impact.
“We had a general idea that this asteroid may have come from the Moon, but the smoking gun was when we found out that it was rich in silicate minerals — not the kind that are seen on asteroids but those that have been found in lunar rock samples,” said Teddy Kareta, an astronomer at Lowell Observatory in Arizona, who led the research. “It looks like it hasn’t been in space for very long, maybe just a few thousand years or so, as there’s a lack of space weathering that would have caused its spectrum to redden.”
The asteroid was first detected on Aug. 7, 2024, by the NASA-funded Sutherland, South Africa, telescope of the University of Hawai’i’s Asteroid Terrestrial-impact Last Alert System (ATLAS). Kareta’s team then used observations from the Lowell Discovery Telescope and the NASA Infrared Telescope Facility (IRTF) at the Mauna Kea Observatory in Hawai’i to show that the spectrum of reflected sunlight from the small object’s surface didn’t match that of any known asteroid type; instead, the reflected light more closely matched rock from the Moon.
Not (Old) Rocket Science
A second clue came from observing how the object moves. Along with asteroids, Space Age debris, such as old rockets from historic launches, can also be found in Earth-like orbits.
The difference in their orbits has to do with how each type responds to solar radiation pressure, which comes from the momentum of photons — quantum particles of light from the Sun — exerting a tiny force when they hit a solid object in space. This momentum exchange from many photons over time can push an object around ever so slightly, speeding it up or slowing it down. While a human-made object, like a hollow rocket booster, will move like an empty tin can in the wind, a natural object, such as an asteroid, will be much less affected.
Researchers studying asteroid 2024 PT5 have plotted its looping motion on two graphs. To a trained eye, they show that the object never gets captured by Earth’s gravity but, instead, lingers nearby before continuing its orbit around the Sun. NASA/JPL-Caltech To rule out 2024 PT5 being space junk, scientists at NASA’s Center for Near Earth Object Studies (CNEOS), which is managed by the agency’s Jet Propulsion Laboratory in Southern California, analyzed its motion. Their precise calculations of the object’s motion under the force of gravity ultimately enabled them to search for additional motion caused by solar radiation pressure. In this case, the effects were found to be too small for the object to be artificial, proving 2024 PT5 is most likely of natural origin.
“Space debris and space rocks move slightly differently in space,” said Oscar Fuentes-Muñoz, a study coauthor and NASA postdoctoral fellow at JPL working with the CNEOS team. “Human-made debris is usually relatively light and gets pushed around by the pressure of sunlight. That 2024 PT5 doesn’t move this way indicates it is much denser than space debris.”
Asteroid Lunar Studies
The discovery of 2024 PT5 doubles the number of known asteroids thought to originate from the Moon. Asteroid 469219 Kamo’oalewa was found in 2016 with an Earth-like orbit around the Sun, indicating that it may also have been ejected from the lunar surface after a large impact. As telescopes become more sensitive to smaller asteroids, more potential Moon boulders will be discovered, creating an exciting opportunity not only for scientists studying a rare population of asteroids, but also for scientists studying the Moon.
If a lunar asteroid can be directly linked to a specific impact crater on the Moon, studying it could lend insights into cratering processes on the pockmarked lunar surface. Also, material from deep below the lunar surface — in the form of asteroids passing close to Earth — may be accessible to future scientists to study.
“This is a story about the Moon as told by asteroid scientists,” said Kareta. “It’s a rare situation where we’ve gone out to study an asteroid but then strayed into new territory in terms of the questions we can ask of 2024 PT5.”
The ATLAS, IRTF, and CNEOS projects are funded by NASA’s planetary defense program, which is managed by the Planetary Defense Coordination Office at NASA Headquarters in Washington.
For more information about asteroids and comets, visit:
https://www.jpl.nasa.gov/topics/asteroids/
NASA Asteroid Experts Create Hypothetical Impact Scenario for Exercise NASA Researchers Discover More Dark Comets Lesson Plan: How to Explore an Asteroid News Media Contacts
Ian J. O’Neill
Jet Propulsion Laboratory, Pasadena, Calif.
818-354-2649
ian.j.oneill@jpl.nasa.gov
Karen Fox / Molly Wasser
NASA Headquarters, Washington
202-358-1600
karen.c.fox@nasa.gov / molly.l.wasser@nasa.gov
Kevin Schindler
Lowell Observatory Public Information Officer
928-607-1387
kevin@lowell.edu
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Last Updated Jan 22, 2025 Related Terms
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By NASA
NASA’s Jet Propulsion Laboratory used radar data taken by ESA’s Sentinel-1A satellite before and after the 2015 eruption of the Calbuco volcano in Chile to create this inter-ferogram showing land deformation. The color bands west of the volcano indicate land sinking. NISAR will produce similar images.ESA/NASA/JPL-Caltech A SAR image — like ones NISAR will produce — shows land cover on Mount Okmok on Alaska’s Umnak Island . Created with data taken in August 2011 by NASA’s UAVSAR instrument, it is an example of polarimetry, which measures return waves’ orientation relative to that of transmitted signals.NASA/JPL-Caltech Data from NASA’s Magellan spacecraft, which launched in 1989, was used to create this image of Crater Isabella, a 108-mile-wide (175-kilometer-wide) impact crater on Venus’ surface. NISAR will use the same basic SAR principles to measure properties and characteristics of Earth’s solid surfaces.NASA/JPL-Caltech Set to launch within a few months, NISAR will use a technique called synthetic aperture radar to produce incredibly detailed maps of surface change on our planet.
When NASA and the Indian Space Research Organization’s (ISRO) new Earth satellite NISAR (NASA-ISRO Synthetic Aperture Radar) launches in coming months, it will capture images of Earth’s surface so detailed they will show how much small plots of land and ice are moving, down to fractions of an inch. Imaging nearly all of Earth’s solid surfaces twice every 12 days, it will see the flex of Earth’s crust before and after natural disasters such as earthquakes; it will monitor the motion of glaciers and ice sheets; and it will track ecosystem changes, including forest growth and deforestation.
The mission’s extraordinary capabilities come from the technique noted in its name: synthetic aperture radar, or SAR. Pioneered by NASA for use in space, SAR combines multiple measurements, taken as a radar flies overhead, to sharpen the scene below. It works like conventional radar, which uses microwaves to detect distant surfaces and objects, but steps up the data processing to reveal properties and characteristics at high resolution.
To get such detail without SAR, radar satellites would need antennas too enormous to launch, much less operate. At 39 feet (12 meters) wide when deployed, NISAR’s radar antenna reflector is as wide as a city bus is long. Yet it would have to be 12 miles (19 kilometers) in diameter for the mission’s L-band instrument, using traditional radar techniques, to image pixels of Earth down to 30 feet (10 meters) across.
Synthetic aperture radar “allows us to refine things very accurately,” said Charles Elachi, who led NASA spaceborne SAR missions before serving as director of NASA’s Jet Propulsion Laboratory in Southern California from 2001 to 2016. “The NISAR mission will open a whole new realm to learn about our planet as a dynamic system.”
Data from NASA’s Magellan spacecraft, which launched in 1989, was used to create this image of Crater Isabella, a 108-mile-wide (175-kilometer-wide) impact crater on Venus’ surface. NISAR will use the same basic SAR principles to measure properties and characteristics of Earth’s solid surfaces.NASA/JPL-Caltech How SAR Works
Elachi arrived at JPL in 1971 after graduating from Caltech, joining a group of engineers developing a radar to study Venus’ surface. Then, as now, radar’s allure was simple: It could collect measurements day and night and see through clouds. The team’s work led to the Magellan mission to Venus in 1989 and several NASA space shuttle radar missions.
An orbiting radar operates on the same principles as one tracking planes at an airport. The spaceborne antenna emits microwave pulses toward Earth. When the pulses hit something — a volcanic cone, for example — they scatter. The antenna receives those signals that echo back to the instrument, which measures their strength, change in frequency, how long they took to return, and if they bounced off of multiple surfaces, such as buildings.
This information can help detect the presence of an object or surface, its distance away, and its speed, but the resolution is too low to generate a clear picture. First conceived at Goodyear Aircraft Corp. in 1952, SAR addresses that issue.
“It’s a technique to create high-resolution images from a low-resolution system,” said Paul Rosen, NISAR’s project scientist at JPL.
As the radar travels, its antenna continuously transmits microwaves and receives echoes from the surface. Because the instrument is moving relative to Earth, there are slight changes in frequency in the return signals. Called the Doppler shift, it’s the same effect that causes a siren’s pitch to rise as a fire engine approaches then fall as it departs.
Computer processing of those signals is like a camera lens redirecting and focusing light to produce a sharp photograph. With SAR, the spacecraft’s path forms the “lens,” and the processing adjusts for the Doppler shifts, allowing the echoes to be aggregated into a single, focused image.
Using SAR
One type of SAR-based visualization is an interferogram, a composite of two images taken at separate times that reveals the differences by measuring the change in the delay of echoes. Though they may look like modern art to the untrained eye, the multicolor concentric bands of interferograms show how far land surfaces have moved: The closer the bands, the greater the motion. Seismologists use these visualizations to measure land deformation from earthquakes.
Another type of SAR analysis, called polarimetry, measures the vertical or horizontal orientation of return waves relative to that of transmitted signals. Waves bouncing off linear structures like buildings tend to return in the same orientation, while those bouncing off irregular features, like tree canopies, return in another orientation. By mapping the differences and the strength of the return signals, researchers can identify an area’s land cover, which is useful for studying deforestation and flooding.
Such analyses are examples of ways NISAR will help researchers better understand processes that affect billions of lives.
“This mission packs in a wide range of science toward a common goal of studying our changing planet and the impacts of natural hazards,” said Deepak Putrevu, co-lead of the ISRO science team at the Space Applications Centre in Ahmedabad, India.
Learn more about NISAR at:
https://nisar.jpl.nasa.gov
News Media Contacts
Andrew Wang / Jane J. Lee
Jet Propulsion Laboratory, Pasadena, Calif.
626-379-6874 / 818-354-0307
andrew.wang@jpl.nasa.gov / jane.j.lee@jpl.nasa.gov
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Last Updated Jan 21, 2025 Related Terms
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6 Min Read NASA International Space Apps Challenge Announces 2024 Global Winners
The 2024 NASA Space Apps Challenge was hosted at 485 events in 163 countries and territories. Credits: NASA NASA Space Apps has named 10 global winners, recognizing teams from around the world for their exceptional innovation and collaboration during the 2024 NASA Space Apps Challenge. As the largest annual global hackathon, this event invites participants to leverage open data from NASA and its space agency partners to tackle real-world challenges on Earth and in space.
Last year’s hackathon welcomed 93,520 registered participants, including space, science, technology, and storytelling enthusiasts of all ages. Participants gathered at local events in 163 countries and territories, forming teams to address the challenges authored by NASA subject matter experts. These challenges included subjects/themes/questions in ocean ecosystems, exoplanet exploration, Earth observation, planetary seismology, and more.
The 2024 Global Winners were determined out of 9,996 project submissions and judged by subject matter experts from NASA and space agency partners.
“These 10 exceptional teams created projects that reflect our commitment to understanding our planet and exploring beyond, with the potential to transform Earth and space science for the benefit of all,” said Dr. Keith Gaddis, NASA Space Apps Challenge program scientistat NASA Headquarters in Washington. “The NASA Space Apps Challenge showcases the potential of every idea and individual. I am excited to see how these innovators will shape and inspire the future of science and exploration.”
You can watch the Global Winners Announcement here to meet these winning teams and learn about the inspiration behind their projects.
2024 NASA Space Apps Challenge Global Winners
Best Use of Science Award: WMPGang
Team Members: Dakota C., Ian C., Maximilian V., Simon S.
Challenge: Create an Orrery Web App that Displays Near-Earth Objects
Country/Territory: Waterloo,Canada
Using their skills in programming, data analysis, and visualization, WMPGang created a web app that identifies satellite risk zones using real-time data on Near-Earth Objects and meteor streams.
Learn more about WMPGang’s SkyShield: Protecting Earth and Satellites from Space Hazards project Best Use of Data Award: GaamaRamma
Team Members: Aakash H., Arun G., Arthur A., Gabriel A., May K.
Challenge: Leveraging Earth Observation Data for Informed Agricultural Decision-Making
Country/Territory: Universal Event, United States
GaamaRamma’s team of tech enthusiasts aimed to create a sustainable way to help farmers efficiently manage water availability in the face of drought, pests, and disease.
Learn more about GaamaRamma’s Waterwise project Best Use of Technology Award: 42 QuakeHeroes
Team Members: Alailton A., Ana B., Gabriel C., Gustavo M., Gustavo T., Larissa M.
Challenge: Seismic Detection Across the Solar System
Country/Territory: Maceió, Brazil
Team 42 QuakeHeroes employed a deep neural network model to identify the precise locations of seismic events within time-series data. They used advanced signal processing techniques to isolate and analyze unique components of non-stationary signals.
Learn more about 42 QuakeHeroes’ project Galactic Impact Award: NVS-knot
Team Members: Oksana M., Oleksandra M., Prokipchyn Y., Val K.
Challenge: Leveraging Earth Observation Data for Informed Agricultural Decision-Making
Country/Territory: Kyiv, Ukraine
The NVS-knot team assessed planting conditions using surface soil moisture and evapotranspiration data, then created an app that empowers farmers to manage planting risks.
Learn more about NVS-knot’s 2plant | ! 2plant project Best Mission Concept Award: AsturExplorers
Team Members: Coral M., Daniel C., Daniel V., Juan B., Samuel G., Vladimir C.
Challenge: Landsat Reflectance Data: On the Fly and at Your Fingertips
Country/Territory: Gijón, Spain
AsturExplorers created Landsat Connect, a web app that provides a simple, intuitive way to track Landast satellites and access Landsat surface reflectance data. The app also allows users to set a target location and receive notifications when Landsat satellites pass over their area.
Learn more about AsturExplorers’ Landsat Connect project Most Inspirational Award: Innovisionaries
Team Members: Rikzah K., Samira K., Shafeeqa J., Umamah A.
Challenge: SDGs in the Classroom
Country/Territory: Sharjah, United Arab Emirates
Innovisionaries developed Eco-Metropolis to inspire sustainability through gameplay. This city-building game engages players in making critical urban planning and resource management decisions based on real-world environmental data.
Learn more about Innovisionaries’ Eco-Metropolis: Sustainable City Simulation project Best Storytelling Award: TerraTales
Team Members: Ahmed R., Fatma E., Habiba A., Judy A., Maya M.
Challenge: Tell Us a Climate Story!
Country/Territory: Cairo, Egypt
TerraTales shared stories of how Earth’s changing climate affects three unique regions: Egypt, Brazil, and Germany. The web app also features an artificial intelligence (AI) model for climate forecasting and an interactive game to encourage users to make eco-friendly choices.
Learn more about TerraTale’s project Global Connection Award: Asteroid Destroyer
Team Members: Kapeesh K., Khoi N., Sathyajit L., Satyam S.
Challenge: Navigator for the Habitable Worlds Observatory (HWO): Mapping the Characterizable Exoplanets in our Galaxy
Country/Territory: Saskatoon, Canada
Team Asteroid Destroyer honed in on exoplanets, utilizing data processing and machine learning techniques to map exoplanets based on size, temperature, and distance.
Learn more about Asteroid Destroyer’s project Art & Technology Award: Connected Earth Museum
Team Members: Gabriel M., Luc R., Lucas R., Mattheus L., Pedro C., Riccardo S.
Challenge: Imagine our Connected Earth
Country/Territory: Campinas, Brazil
Team Connected Earth Museum created an immersive virtual museum experience to raise awareness of Earth’s changing climate. An AI host guides users through an interactive gallery featuring 3D and 2D visualizations, including a time series on Earth and ocean temperatures, population density, wildfires, and more.
Learn more about Connected Earth Museums’ project Local Impact Award: Team I.O.
Team Members: Frank R., Jan K., Raphael R., Ryan Z., Victoria M.
Challenge: Community Mapping
Country/Territory: Florianópolis, Brazil
Team I.O. bridges the gap between complex Geographic Information Systems data and user-friendly communication, making critical environmental information accessible to everyone, regardless of technical expertise.
Learn more about Team I.O.’s G.R.O.W. (Global Recovery and Observation of Wildfires) project Want to take part in the 2025 NASA Space Apps Challenge? Mark your calendars for October 4 and 5! Registration will open in July. At that time, participants will be able to register for a local event hosted by NASA Space Apps leads from around the world. You can stay connected with NASA Space Apps on Facebook, Instagram, and X.
Space Apps is funded by NASA’s Earth Science Division through a contract with Booz Allen Hamilton, Mindgrub, and SecondMuse.
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Last Updated Jan 16, 2025 Related Terms
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