Feed aggregator
Tiny nematode worms can grow enormous mouths and become cannibals
Tiny nematode worms can grow enormous mouths and become cannibals
Geoscientists are using telecom 'dark fibres' to map Earth’s innards
Geoscientists are using telecom 'dark fibres' to map Earth’s innards
NASA's Mars sample return plan is getting a major overhaul: 'The bottom line is $11 billion is too expensive'
SWOT Satellite Helps Gauge the Depth of Death Valley’s Temporary Lake
Data from the international Surface Water and Ocean Topography mission helped researchers to calculate the depth of water in this transient freshwater body.
California’s Death Valley, the driest place in North America, has hosted an ephemeral lake since late 2023. A NASA-led analysis recently calculated water depths in the temporary lake over several weeks in February and March 2024, demonstrating the capabilities of the U.S.-French Surface Water and Ocean Topography (SWOT) satellite, which launched in December 2022.
The analysis found that water depths in the lake ranged from about 3 feet (1 meter) to less than 1.5 feet (0.5 meters) over the course of about 6 weeks. This period included a series of storms that swept across California, bringing record amounts of rainfall.
To estimate the depth of the lake, known informally as Lake Manly, researchers used water level data collected by SWOT and subtracted corresponding U.S. Geological Survey land elevation information for Badwater Basin.
The researchers found that the water levels varied across space and time in the roughly 10-day period between SWOT observations. In the visualization above, water depths of about 3 feet (1 meter) appear dark blue; those of less than 1.5 feet (0.5 meters) appear light yellow. Right after a series of storms in early February, the temporary lake was about 6 miles (10 kilometers) long and 3 miles (5 kilometers) wide. Each pixel in the image represents an area that is about 330 feet by 330 feet (100 meters by 100 meters).
To view this video please enable JavaScript, and consider upgrading to a web browser that supports HTML5 video
Using data from SWOT, this video shows changes in water depth for Death Valley’s temporary lake from February into March of this year. Depths ranged between about 3 feet (1 meter) deep (dark blue) to less than 1.5 feet (0.5 meters) deep (light yellow). Credit: NASA/JPL-Caltech“This is a really cool example of how SWOT can track how unique lake systems work,” said Tamlin Pavelsky, the NASA freshwater science lead for SWOT and a hydrologist at the University of North Carolina, Chapel Hill.
Unlike many lakes around the world, Death Valley’s lake is temporary, relatively shallow, and strong winds are enough to move the freshwater body a couple of miles, as happened from Feb. 29 to March 2. Since there isn’t typically water in Badwater Basin, researchers don’t have permanent instruments in place for studying water in this area. SWOT can fill the data gap for when places like this, and others around the world, become inundated.
Since shortly after launch, SWOT has been measuring the height of nearly all water on Earth’s surface, developing one of the most detailed and comprehensive views of the planet’s oceans and freshwater lakes and rivers. Not only can the satellite detect the extent of water, as other satellites can, but SWOT is also able to measure water surface levels. Combined with other types of information, SWOT measurements can yield water depth data for inland features like lakes and rivers.
The SWOT science team makes its measurements using the Ka-band Radar Interferometer (KaRIn) instrument. With two antennas spread 33 feet (10 meters) apart on a boom, KaRIn produces a pair of data swaths as it circles the globe, bouncing radar pulses off water surfaces to collect surface-height information.
“We’ve never flown a Ka-band radar like the KaRIn instrument on a satellite before,” said Pavelsky, so the data represented by the graphic above is also important for scientists and engineers to better understand how this kind of radar works from orbit.
More About the MissionLaunched in December 2022 from Vandenberg Space Force Base in central California, SWOT is now in its operations phase, collecting data that will be used for research and other purposes.
SWOT was jointly developed by NASA and the French space agency, CNES (Centre National d’Études Spatiales), with contributions from the Canadian Space Agency (CSA) and the UK Space Agency. NASA’s Jet Propulsion Laboratory, which is managed for the agency by Caltech in Pasadena, California, leads the U.S. component of the project. For the flight system payload, NASA provided the KaRIn instrument, a GPS science receiver, a laser retroreflector, a two-beam microwave radiometer, and NASA instrument operations. CNES provided the Doppler Orbitography and Radioposition Integrated by Satellite (DORIS) system, the dual frequency Poseidon altimeter (developed by Thales Alenia Space), the KaRIn radio-frequency subsystem (together with Thales Alenia Space and with support from the UK Space Agency), the satellite platform, and ground operations. CSA provided the KaRIn high-power transmitter assembly. NASA provided the launch vehicle and the agency’s Launch Services Program, based at Kennedy Space Center, managed the associated launch services.
To learn more about SWOT, visit:
News Media ContactsJane J. Lee / Andrew Wang
Jet Propulsion Laboratory, Pasadena, Calif.
818-354-0307 / 626-379-6874
jane.j.lee@jpl.nasa.gov / andrew.wang@jpl.nasa.gov
2024-043
Share Details Last Updated Apr 15, 2024 Related Terms Explore More 4 min read The Ocean Touches Everything: Celebrate Earth Day with NASA Article 4 days ago 3 min read Tech Today: Folding NASA Experience into an Origami ToolkitMath for designing lasers becomes artist’s key to creating complex crease patterns
Article 4 days ago 4 min read Media Get Close-Up of NASA’s Jupiter-Bound Europa Clipper Article 5 days agoSeeing the Solar Eclipse from 223,000 Miles Away
Seeing the Solar Eclipse from 223,000 Miles Away
NASA’s Lunar Reconnaissance Orbiter (LRO) captured the April 8, 2024, solar eclipse from hundreds of thousands of miles away. The camera suite aboard the LRO usually retrieves high resolution black and white images of the Moon’s surface; these images provide knowledge of polar illumination conditions, identify potential resources, hazards, and enable safe landing site selection. To take an image of Earth, the LRO has to rapidly rotate to build up the image.
Learn more about the LRO’s cameras and how this image was taken.
Image Credit: NASA/Goddard/Arizona State University
NASA astronaut Loral O'Hara missed the total solar eclipse, but saw Earth 'moving' below her during spacewalk (photos)
NASA Welcomes Switzerland as Newest Artemis Accords Signatory
Switzerland became the 37th country to sign the Artemis Accords at NASA Headquarters in Washington on Monday, April 15, affirming Switzerland’s commitment to the sustainable and beneficial use of space for all humankind.
“Today, we marked a giant leap forward in the partnership between the United States and Switzerland,” said NASA Administrator Bill Nelson. “As we welcome you into the Artemis Accords family, we expand our commitment to explore the unknown openly and peacefully. Discovery strengthens goodwill on Earth, and we are excited to expand our countries’ shared values and principles to the cosmos.”
At approximately 11:30 a.m., Guy Parmelin, Swiss Federal Councillor and Minister for Economic Affairs, Education & Research, signed the Accords on behalf of Switzerland. Other participants in the ceremony included:
- Valda Vikmanis-Keller, acting deputy assistant secretary, Department of State
- Martina Hirayama, state secretary, Head of the State Secretariat for Education, Research, and Innovation
- Jacques Pitteloud, Swiss Ambassador to the U.S.
- ESA (European Space Agency) astronaut Marco Sieber, Swiss national
- Renato Krpoun, Head of Swiss Space Office
- Professor Peter Wurz, Director Space and Planetary Sciences, University of Bern
“Switzerland has a long-standing partnership with NASA on human space exploration as well as space and Earth sciences,” said Parmelin. “With the signature of the Artemis Accords we renew our commitment to jointly explore the heavens above us.”
The Artemis Accords, established by NASA and the U.S. Department of State in 2020, reinforce the 1968 Treaty on Principles Governing the Activities of States in the Exploration and Use of Outer Space, Including the Moon and Other Celestial Bodies otherwise known as the Outer Space Treaty. They also emphasize a commitment on behalf of the U.S. to the Registration Convention, the Agreement on the Rescue of Astronauts, and other standards that NASA and its partners support.
Many more countries are anticipated to join the Artemis Accords in the months and years to come, as NASA continues to facilitate a safe, peaceful, and prosperous future in space with its international partners.
For more information on the Artemis Accords, visit:
https://www.nasa.gov/artemis-accords
-end-
Lauren Low
Headquarters, Washington
202-358-1600
lauren.e.low@nasa.gov
NASA Struggles to Find Way Forward for Mars Sample Return
NASA's Perseverance mission has been collecting samples for later retrieval and return to Earth. Now, it's unclear how we'll get those samples home.
The post NASA Struggles to Find Way Forward for Mars Sample Return appeared first on Sky & Telescope.
You Can't Know the True Size of an Exoplanet Without Knowing its Star's Magnetic Field
In 2011, astronomers with the Wide Angle Search for Planets (WASP) consortium detected a gas giant orbiting very close to a Sun-like (G-type) star about 700 light-years away. This planet is known as WASP-39b (aka. “Bocaprins”), one of many “hot Jupiters” discovered in recent decades that orbits its star at a distance of less than 5% the distance between the Earth and the Sun (0.05 AU). In 2022, shortly after the James Webb Space Telescope (JWST) it became the first exoplanet to have carbon dioxide and sulfur dioxide detected in its atmosphere.
Alas, researchers have not constrained all of WASP-39b’s crucial details (particularly its size) based on the planet’s light curves, as observed by Webb. which is holding up more precise data analyses. In a new study led by the Max Planck Institute for Solar System Research (MPS), an international team has shown a way to overcome this obstacle. They argue that considering a parent star’s magnetic field, the true size of an exoplanet in orbit can be determined. These findings are likely to significantly impact the rapidly expanding field of exoplanet study and characterization.
The study was led by Dr. Nadiia M. Kostogryz and her fellow researchers from the MPS. They were joined by astronomers and astrophysicists from the Center for Astronomy (Heidelberg University), the Astrophysics Group at Keele University, the Kavli Institute for Astrophysics and Space Research at the Massachusetts Institute of Technology (MIT), and the Space Telescope Science Institute (STScI). The paper describing their research, “Magnetic origin of the discrepancy between stellar limb-darkening models and observations,” was recently published in Nature Astronomy.
The “hot Jupiter” exoplanet WASP-69b orbits its star so closely that its atmosphere is being blown into space. Credit: Adam Makarenko/W. M. Keck ObservatoryA light curve is the measurement of a star’s brightness over longer periods. Using the Transit Method (Transit Photometry), astronomers monitor stars for periodic dips in brightness, which can result from an exoplanet passing (transiting) in front of their face relative to the observer. In addition to being the most widely used method for detecting exoplanets, precise observations of light curves allow astronomers to estimate the size and orbital period of the exoplanets.
These curves can also reveal information about the composition of the planet’s atmosphere based on light passing through its atmosphere as it makes a transit – a technique known as “transit spectroscopy.” Unfortunately, estimates on planet size suffer from an observational issue known as “limb darkening.” Dr. Kostogryz explained in an MPS press statement:
“The problems arising when interpreting the data from WASP-39b are well known from many other exoplanets – regardless [of] whether they are observed with Kepler, TESS, James Webb, or the future PLATO spacecraft. As with other stars orbited by exoplanets, the observed light curve of WASP-39 is flatter than previous models can explain.”
The edge of the stellar disk (or “limb”) plays a decisive role in interpreting a star’s light curve. Since the limb corresponds to the star’s outer (and cooler) layers, it appears darker to the observer than the inner area. However, the star does not actually shine less brightly further out. This “limb darkening” affects the shape of the exoplanet signal in the light curve, as the dimming determines how steeply the curve falls during a planetary transit and then rises again. Historically, astronomers have not been able to reproduce observational data using conventional stellar models accurately.
In every case, the decrease in the star’s brightness was less abrupt than model calculations predicted. Clearly, something was missing from the models that prevented astronomers from reproducing exoplanet transit signals. As Dr. Kostogryz and her team discovered, the missing piece is stellar magnetic fields, which are generated by the motion of conductive plasma inside a star. The team first noticed this when examining selected light curves obtained by NASA’s Kepler Space Telescope between 2009 and 2018.
An illustration of Earth’s magnetic field. Credit: ESA/ATG medialabThe researchers also proved that the discrepancy between observational data and model calculations disappears if the star’s magnetic field is included in the computations. To this end, the team turned to selected data from NASA’s Kepler Space Telescope, which captured the light of thousands and thousands of stars from 2009 to 2018. To this end, they modeled the atmosphere of typical Kepler stars in the presence of a magnetic field and then simulated observational data based on these calculations. When they compared their results to real data, they found it accurately reproduced Kepler’s observations.
They also found that the strength of the magnetic field can have a profound effect, where limb darkening is more pronounced in stars with weak magnetic fields and less in stars with strong ones. Lastly, they extended their simulations to emission spectra data obtained by the JWST and found that the magnetic field of the parent star influences limb darkening differently at different wavelengths. These findings will help inform future exoplanet studies, leading to more precise estimates of the planets’ characteristics. Said Dr. Alexander Shapiro, coauthor of the current study and head of an ERC-funded research group at the MPS:
“In the past decades and years, the way to move forward in exoplanet research was to improve the hardware, the space telescopes designed to search for and characterize new worlds. The James Webb Space Telescope has pushed this development to new limits. The next step is now to improve and refine the models to interpret this excellent data.”
The researchers now plan to extend their analyses to stars different from the Sun, which could lead to refined estimates of exoplanet mass for rocky planets (similar to Earth). In addition, their findings indicate that the light curves of stars could be used to constrain the strength of stellar magnetic fields, another characteristic that is challenging to measure.
Further Reading: MPS, Nature Astronomy
The post You Can't Know the True Size of an Exoplanet Without Knowing its Star's Magnetic Field appeared first on Universe Today.
These 3 stars are losing weight fast — thanks to stellar winds way stronger than the sun's
Space-based solar power may be one step closer to reality, thanks to this key test (video)
Parkinson's disease progression slowed by antibody infusions
Parkinson's disease progression slowed by antibody infusions
NASA Sets Path to Return Mars Samples, Seeks Innovative Designs
NASA Administrator Bill Nelson shared on Monday the agency’s path forward on the Mars Sample Return program, including seeking innovative designs to return valuable samples from Mars to Earth. Such samples will not only help us understand the formation and evolution of our solar system but can be used to prepare for future human explorers and to aid in NASA’s search for signs of ancient life.
Over the last quarter century, NASA has engaged in a systematic effort to determine the early history of Mars and how it can help us understand the formation and evolution of habitable worlds, including Earth. As part of that effort, Mars Sample Return has been a long-term goal of international planetary exploration for the past two decades. NASA’s Perseverance rover has been collecting samples for later collection and return to Earth since it landed on Mars in 2021.
“Mars Sample Return will be one of the most complex missions NASA has ever undertaken. The bottom line is, an $11 billion budget is too expensive, and a 2040 return date is too far away,” said Nelson. “Safely landing and collecting the samples, launching a rocket with the samples off another planet – which has never been done before – and safely transporting the samples more than 33 million miles back to Earth is no small task. We need to look outside the box to find a way ahead that is both affordable and returns samples in a reasonable timeframe.”
The agency also has released NASA’s response to a Mars Sample Return Independent Review Board report from September 2023. This includes: an updated mission design with reduced complexity; improved resiliency; risk posture; stronger accountability and coordination; and an overall budget likely in the $8 billion to $11 billion range. Given the Fiscal Year 2025 budget and anticipated budget constraints, as well as the need to maintain a balanced science portfolio, the current mission design will return samples in 2040.
To achieve the ambitious goal of returning the key samples to Earth earlier and at a lower cost, the agency is asking the NASA community to work together to develop a revised plan that leverages innovation and proven technology. Additionally, NASA soon will solicit architecture proposals from industry that could return samples in the 2030s, and lowers cost, risk, and mission complexity.
“NASA does visionary science – and returning diverse, scientifically-relevant samples from Mars is a key priority,” said Nicky Fox, associate administrator, Science Mission Directorate, at NASA Headquarters in Washington. “To organize a mission at this level of complexity, we employ decades of lessons on how to run a large mission, including incorporating the input we get from conducting independent reviews. Our next steps will position us to bring this transformational mission forward and deliver revolutionary science from Mars – providing critical new insights into the origins and evolution of Mars, our solar system, and life on Earth.”
For more information about NASA’s research at Mars, visit:
-end-
Dewayne Washington / Karen Fox
Headquarters, Washington
202-358-1600
dewayne.a.washington@nasa.gov / karen.fox@nasa.gov