TL;DR
- Scientists have directly measured wind speed on a brown dwarf, an object larger than Jupiter (the largest planet in our solar system) but not quite massive enough to become a star. To achieve the finding, they used a new method that could also be applied to learn about the atmospheres of gas-dominated planets outside our solar system.
- New analysis of data from NASA’s Cassini spacecraft found that electric currents, triggered by interactions between solar winds and charged particles from Saturn’s moons, spark the auroras and heat the planet’s upper atmosphere.
- By combining the power of strong gravitational lensing with the capability of the Atacama Large Millimeter/submillimeter Array (ALMA), a team of astronomers from Japan and Taiwan imaged disturbed gaseous clouds in a distant quasar called MG J0414+0534; the researchers also found that the disruption is caused by supermassive black hole jets.
- The new Russian-German observatory “Spektr-RG” has been filming the galaxy and beyond since December 2019, and was tasked with coming up with an exceptionally high-resolution x-ray image of the universe.
- Astronomers have found the best evidence for the perpetrator of a cosmic homicide: a black hole of an elusive class known as ‘intermediate-mass,’ which betrayed its existence by tearing apart a wayward star that passed too close.
- Researchers probed Martian meteorites to reconstruct Mars’ chaotic history. Their findings suggest that Mars might not have had a global magma ocean.
- First-ever photo proof of powerful jet emerging from colliding galaxies
- The Milky Way’s satellites help reveal link between dark matter halos and galaxy formation
- Aerospace engineering researchers developed an algorithm that can run onboard a vehicle, providing important real-time data to aid in steering the craft, particularly during the crucial entry, descent, and landing stage.
- NASA researchers have developed new satellite-based, weekly global maps of soil moisture and groundwater wetness conditions.
- Astronomers detect first double helium-core white dwarf gravitational wave source
- Newly discovered single-celled creatures living deep beneath the seafloor have provided clues about how to find life on Mars. These bacteria were discovered living in tiny cracks inside volcanic rocks after researchers perfected a new method cutting rocks into ultrathin slices to study under a microscope. Researchers estimate that the rock cracks are home to a community of bacteria as dense as that of the human gut, about 10 billion bacterial cells per cubic centimeter.
- Chemists have created a hybrid system of bacteria and nanowires that captures energy from sunlight and transfers it to the bacteria to turn carbon dioxide and water into organic molecules and oxygen. On Earth, such a biohybrid could remove carbon dioxide from the atmosphere. On Mars, it would provide colonists with raw material to manufacture organic compounds ranging from fuels to drugs. The efficiency is greater than the photosynthetic efficiency of most plants.
- Donald Trump: NASA needs to have another Moon landing in next five years
- NASA report outlines vision for long-term human lunar exploration
- Boeing will launch a 2nd uncrewed test flight of its Starliner spacecraft for NASA
- UK’s Galileo rival delayed amid wrangling and rising costs
- Jeff Bezos’ rocket company is reportedly pushing employees to travel from Washington to Texas to help launch a space tourism rocket despite the coronavirus outbreak
- White House looks for international support for space resource rights
- Pandemic pushes SpaceX GPS 3 launch to late June
- Astronauts share isolation workout tips from space (video)
- And much more!
Space industry in numbers
Last summer, the Space Foundation published the second-quarter findings of its 2019 issue of The Space Report, revealing that:
- The global space economy grew 8.1% in 2018 to USA 414.75 billion, exceeding USD 400 billion for the first time.
- Global launches in 2018 increased by 46% over the number of launches a decade ago.
- Global launches in 2018 exceeded 100 for the first time since 1990.
Analysts at Morgan Stanley and Goldman Sachs have predicted that economic activity in space will become a multi-trillion-dollar market in the coming decades. Morgan Stanley’s Space Team estimates that the roughly USD 350 billion global space industry could surge to over USD 1 trillion by 2040.
Space industry news
Boeing will launch a 2nd uncrewed test flight of its Starliner spacecraft for NASA
Boeing will take another crack at an uncrewed rendezvous with the International Space Station (ISS).
In December 2019, the company launched its CST-100 Starliner capsule to the ISS on an uncrewed demonstration mission called Orbital Flight Test (OFT), which was intended to show that the spacecraft can safely carry NASA astronauts.
But things didn’t go as planned: Starliner suffered a glitch with its onboard timing system, got stranded in the wrong orbit and was brought down for a safe landing after circling Earth by itself for two days.
Analyses of OFT data subsequently revealed several serious software issues. Still, it remained unclear whether Boeing would launch another OFT or proceed directly to the next phase of Starliner vetting, a crewed test flight to the ISS.
“We have chosen to refly our Orbital Flight Test to demonstrate the quality of the Starliner system,” Boeing representatives announced in a statement on April 6.
“Flying another uncrewed flight will allow us to complete all flight test objectives and evaluate the performance of the second Starliner vehicle at no cost to the taxpayer,” they added. “We will then proceed to the tremendous responsibility and privilege of flying astronauts to the International Space Station.”
The statement does not indicate when the second OFT will lift off.
Boeing had planned for this outcome financially. The company announced in late January that it was setting aside $410 million in case it was decided to refly OFT.
Boeing has been developing Starliner under a series of NASA contracts. The most recent of these, a $4.2 billion deal signed in 2014, covers the end of development work and the launch of six operational crewed missions to the ISS.
SpaceX is working on its own astronaut taxi, a capsule called Crew Dragon. Elon Musk’s company holds a $2.6 billion NASA deal, also signed in 2014, to get Crew Dragon up and running and fly six missions to the orbiting lab.
Crew Dragon aced its version of OFT, called Demo-1, in March 2019. SpaceX is now gearing up for the Demo-2 crewed test flight, which is scheduled to lift off in mid- to late May.
Related: Boeing’s 1st Starliner flight test in photos
Groundwater and Soil Moisture Conditions from GRACE-FO Data Assimilation for the Contiguous U.S. and Global Land
NASA researchers have developed new satellite-based, weekly global maps of soil moisture and groundwater wetness conditions.
Scientists at NASA’s Goddard Space Flight Center generate groundwater and soil moisture drought indicators each week. They are based on terrestrial water storage observations derived from GRACE-FO satellite data and integrated with other observations, using a sophisticated numerical model of land surface water and energy processes. The drought indicators describe current wet or dry conditions, expressed as a percentile showing the probability of occurrence for that particular location and time of year, with lower values (warm colors) meaning dryer than normal, and higher values (blues) meaning wetter than normal. These are provided as both images and binary data files.
The Contiguous U.S. (CONUS) indicators are generated at 0.125 degree, while the Global Land indicators are at 0.25 degree resolution (Global/Africa/Asia/Australia/Europe/North America/South America areas above).
UK’s Galileo rival delayed amid wrangling and rising costs
Britain’s plan for a new sovereign satellite navigation system — pushed by the government as a symbol of post-Brexit independence — has been delayed for at least six months amid disagreements about the scope and costs of the multibillion pound space project.
Jeff Bezos’s rocket company gets virus lockdown exemption
Employees at Jeff Bezos’ aerospace firm Blue Origin are outraged that senior leadership is pressuring workers to conduct a test launch of the company’s New Shepard rocket — designed to take wealthy tourists into space — while the COVID-19 pandemic devastates the United States.
To conduct the flight, Blue Origin officials are considering transporting employees from the company’s main headquarters in Kent, Washington — a town near Seattle where COVID-19 cases have surged — to a small town in West Texas called Van Horn. The town, which has a population of just over 2,000, is home to Blue Origin’s test launch facility where the company has conducted all past flights of the New Shepard rocket.
Many employees fear that traveling to Van Horn might expose them to the novel coronavirus and inadvertently introduce COVID-19 to the residents of the rural town where there is very little infrastructure to handle an outbreak. The Verge spoke exclusively with four Blue Origin employees who all asked to remain anonymous for fear of retaliation from the company. They say they are frustrated by the company’s desire to conduct a launch, as it could unnecessarily jeopardize the health of employees at Blue Origin and residents of Van Horn.
U.S. Air Force to transfer 23 units to the Space Force
The Department of the Air Force has identified 23 U.S. Air Force organizations with space-related missions that will transfer to the Space Force.
The goal is to transfer 23 Air Force units and 1,840 Air Force billets located at bases in Colorado, California, Nevada, Ohio, New Mexico and Maryland from the Air Force into the Space Force within the next three to six months, the Space Force said March 31.
The 23 units that are moving to the Space Force are in addition to the five Space Wings that already were transferred to the new service when it was enacted into law on Dec. 20, 2019.
The 23 organizations and billets will be reorganized under the Space Force but will not be physically moved to a different geographic location. These units will “remain in place to leverage the talent, infrastructure, and key capabilities at their current location,” said the Space Force announcement.
Third Starship prototype destroyed in tanking test
For the third time in less than five months, a prototype of SpaceX’s Starship next-generation launch vehicle was destroyed in a test at the company’s South Texas facilities April 3, although this failure may an issue with the test itself.
The Starship SN3 vehicle was on the pad at SpaceX’s test site at Boca Chica, Texas, in the early morning hours of April 3 for a cryogenic tanking test, where the vehicle’s propellant tanks are filled with liquid nitrogen. Shortly after 3 a.m. Eastern, the cylindrical vehicle appeared to crumple about halfway up, causing the top part of the vehicle to topple.
More news:
NASA report outlines vision for long-term human lunar exploration
White House looks for international support for space resource rights
Pandemic pushes SpaceX GPS 3 launch to late June
Numerica expands space surveillance services aimed at satellite operators
Thales Alenia Space to build two prototype satellites for constellation venture
NOAA awards first contracts for future satellite constellation
Long March 3B carrying commercial Indonesian satellite fails
Masten wins NASA lunar lander award
Raymond: Space Force acquisition proposals are about ‘going fast’
HASC Chairman: Space Force launch contracts should stay on schedule to help industrial base
Final first-generation cargo Dragon spacecraft returns to Earth
Report criticizes management of ISS National Laboratory
Soon-to-be Space Force officers see opportunity for change
Marshall officials expect center closure to last for weeks
ESA restores operations of space science missions
Chinese commercial rocket sells for $5.6 million in April Fool’s Day auction
Top enlisted leader Towberman officially joins the U.S. Space Force
Space Development Agency to seek bids for its first constellation
Virgin Orbit selects Japanese airport as launch site
Limited work continues on JWST
NASA planning reorganization of human spaceflight directorate
Space Micro wins $3 million for laser communications terminal
Space exploration and cosmology news
A measurement of the wind speed on a brown dwarf
by Katelyn. N. Allers, Johanna M. Vos, Beth A. Biller, Peter. K. G. Williams in Science
For the first time, scientists have directly measured wind speed on a brown dwarf, an object larger than Jupiter (the largest planet in our solar system) but not quite massive enough to become a star. To achieve the finding, they used a new method that could also be applied to learn about the atmospheres of gas-dominated planets outside our solar system.
Brown dwarfs are objects intermediate in mass between large planets and small stars, and their atmospheres share many characteristics with gas giant planets. Wind speeds in Solar System gas giant atmospheres can be derived by comparing the planet’s rotational periods in the infrared (tracing the upper atmosphere) and radio (tied to the interior). Allers et al. observed a nearby brown dwarf, 2MASS J10475385+2124234, and determined its infrared and radio periods. They derived an average wind speed of ∼650 meters per second in a west-to-east direction. This technique should also work for exoplanets.
Zonal (latitudinal) winds dominate the bulk flow of planetary atmospheres. For gas giant planets such as Jupiter, the motion of clouds can be compared with radio emissions from the magnetosphere, which is connected to the planet’s interior, to determine the wind speed. In principle, this technique can be applied to brown dwarfs and/or directly imaged exoplanets if periods can be determined for both the infrared and radio emissions. Researchers apply this method to measure the wind speeds on the brown dwarf 2MASS J10475385+2124234. The difference between the radio period of 1.751 to 1.765 hours and infrared period of 1.741 ± 0.007 hours implies a strong wind (+650 ± 310 meters per second) proceeding eastward. This could be due to atmospheric jet streams and/or low frictional drag at the bottom of the atmosphere.
Cosmic Awakening: Russian Telescope Tapes Flash From Once ‘Silent’ Black Star in Heart of Milky Way
The Russian-German astrophysicist space observatory “Spektr-RG” has discovered that a black hole in the centre of our galaxy that has been “silent” for a quarter of a century, has now woken up, the Institute of Space Research of the Russian Academy of Sciences (RAS) announced in a statement.
“On 1 April, while monitoring the sky, the telescope ART-XC from the orbital observatory ‘Spektr-RG’ registered a bright x-ray source around the centre of the galaxy”, the institute said in the statement.
It added the source appeared to be black hole 4U 1755–338 that was first spotted by the x-ray space observatory Uhuru, but which “fell silent” in 1996 and hasn’t demonstrated any signs of activity since.
The statement says that the institute’s astrophysicists assumed there could be a new flare-ups from this black hole, caused by the resumption of gravity between the black hole and a substance from a nearby star.
The observatory “Spektr-RG” has at its disposal two telescopes: eROSITA, built by the Institute of Extraterrestrial Physics of the Max Planck Society (Germany), and ART-XC, designed by the Russian Institute of Space Research (of RAS) and manufactured in cooperation with the All-Russia Research Institute of Experimental Physics in Sarov, and the Marshall Space Flight Centre in Huntsville, Alabama.
Launched on 13 July 2019, the Russian-German space observatory “Spektr-RG” aims to compile a grand map of the universe, including black holes and decaying neutron stars, in the next four years, after taking high-resolution pictures of the entire sky in the x-ray spectrum. In October, it reached its main working spot located within 1.5 million kilometres from Earth and in December it set about monitoring the sky.
Overall eight maps will be drawn up, with half a year allocated for each of them. The most detailed one, which will combine all eight of the documents, will be completed and made public around 2025.
A pole-to-pole pressure–temperature map of Saturn’s thermosphere from Cassini Grand Finale data
by Z. Brown, T. Koskinen, I. Müller-Wodarg, R. West, A. Jouchoux & L. Esposito in Nature Astronomy
New analysis of data from NASA’s Cassini spacecraft found that electric currents, triggered by interactions between solar winds and charged particles from Saturn’s moons, spark the auroras and heat the planet’s upper atmosphere.
Temperatures of the outer planet thermospheres exceed those predicted by solar heating alone by several hundred degrees. Enough energy is deposited at auroral regions to heat the entire thermosphere, but models predict that equatorward distribution is inhibited by strong Coriolis forces and ion drag. A better understanding of auroral energy deposition and circulation are critical to solving this so-called energy crisis. Stellar occultations observed by the Ultraviolet Imaging Spectrograph instrument during the Cassini Grand Finale were designed to map the thermosphere from pole to pole. Researchers analyse these observations, together with earlier observations from 2016 and 2017, to create a two-dimensional map of densities and temperatures in Saturn’s thermosphere as a function of latitude and depth. The observed temperatures at auroral latitudes are cooler and peak at higher altitudes and lower latitudes than predicted by models, leading to a shallower meridional pressure gradient. Under modified geostrophy, they infer slower westward zonal winds that extend to lower latitudes than predicted, supporting equatorward flow from approximately 70° to 30° latitude in both hemispheres. Researchers also show evidence of atmospheric waves in the data that can contribute to equatorward redistribution of energy through zonal drag.
TXS 2116−077: A Gamma-Ray Emitting Relativistic Jet Hosted in a Galaxy Merger
by Vaidehi S. Paliya, Enrique Pérez, Rubén García-Benito, Marco Ajello, Francisco Prada, Antxon Alberdi, Hyewon Suh, C. H. Ishwara Chandra, Alberto Domínguez in The Astrophysical Journal
First-ever photo proof of powerful jet emerging from colliding galaxies
What triggers collimated relativistic outflows or jets from the centers of galaxies remains a fundamental question in astrophysics. The merging of two galaxies has been proposed to realize the conditions to successfully launch and drive such jets into the intergalactic medium. However, evidence for the operation of this mechanism is scarce. Researchers report the first unambiguous detection of an ongoing merger of a narrow-line Seyfert 1 galaxy, TXS 2116−077, hosting a closely aligned, γ-ray emitting relativistic jet with a Seyfert 2 galaxy at a separation of ~12 kpc, using the observations taken with the 8.2 m Subaru Telescope. Their subsequent follow-up observations with the 10.4 m Gran Telescopio Canarias, 4.2 m William Herschel Telescope, and Chandra X-ray observatory have provided what is likely to be the first glimpse of the merging environment hosting a closely aligned relativistic jet. The finding that the jet is considerably younger than the merger demonstrates that jet activity can be triggered by galaxy mergers and that γ-ray detected narrow-line Seyfert 1 galaxies represent the beginning phase of that activity. These results also highlight the crucial role of mergers in shaping the fate of galaxies in their cosmological evolution and are consistent with recent studies focused on the host galaxy imaging of this enigmatic class of active galactic nuclei.
Milky Way Satellite Census — II. Galaxy-Halo Connection Constraints Including the Impact of the Large Magellanic Cloud
by E. O. Nadler, R. H. Wechsler, K. Bechtol, Y. -Y. Mao, G. Green, A. Drlica-Wagner, M. McNanna, S. Mau, A. B. Pace, J. D. Simon, A. Kravtsov et al.
The Milky Way’s satellites help reveal link between dark matter halos and galaxy formation
The population of Milky Way (MW) satellites contains the faintest known galaxies, and thus provides essential insight into galaxy formation and dark matter microphysics. Researchers combine a model of the galaxy — halo connection with newly derived observational selection functions based on searches for satellites in photometric surveys over nearly the entire high-Galactic-latitude sky. In particular, they use cosmological zoom-in simulations of MW-like halos that include realistic Large Magellanic Cloud (LMC) analogs to fit the position-dependent MW satellite luminosity function. They report decisive evidence for the statistical impact of the LMC on the MW satellite population due to an estimated 6.5±1.5 observed LMC-associated satellites, consistent with the number of LMC satellites inferred from Gaia proper motion measurements, confirming the predictions of cold dark matter models for the existence of satellites within satellite halos. Moreover, scientists infer that the LMC fell into the MW within the last 2 Gyr at high confidence. Based on their detailed full-sky modeling, researchers find that the faintest observed satellites inhabit halos with peak virial masses below 2.2×108 M⊙ at 95% confidence, and they place the first robust constraints on the fraction of halos that host galaxies in this regime. Scientists predict that the faintest detectable satellites occupy halos with peak virial masses above 106 M⊙, highlighting the potential for powerful galaxy formation and dark matter constraints from future dwarf galaxy searches.
Predicting in-flight air density for more accurate landing
Aerospace engineering researchers developed an algorithm that can run onboard a vehicle, providing important real-time data to aid in steering the craft, particularly during the crucial entry, descent, and landing stage.
In the final few minutes of a spacecraft landing it is moving at hypersonic speeds through many layers of atmosphere. Knowing the air density outside of the vehicle can have a substantial effect on its angle of descent and ability to hit a specific landing spot. But air density sensors that can withstand the harsh hypersonic conditions are uncommon. A student from The Netherlands, working with an aerospace engineer at the University of Illinois at Urbana-Champaign, developed an algorithm that can run onboard a vehicle, providing important real-time data to aid in steering the craft, particularly during the crucial entry, descent, and landing stage.
“The algorithm we created can run in-flight, onboard the vehicle and estimate what the atmosphere outside is like,” said Hamza El-Kebir, an undergraduate at Delft University of Technology. “So this is a complete game changer, because now you can use prior knowledge about the vehicle’s motion to estimate the air density, inform your decisions in flight, and make minor alterations in your course. This can provide more certainty that you’re going to hit that spot, instead of dealing with really conservative guidance.”
Deep microbial proliferation at the basalt interface in 33.5–104 million-year-old oceanic crust
by Yohey Suzuki, Seiya Yamashita, Mariko Kouduka, Yutaro Ao, Hiroki Mukai, Satoshi Mitsunobu, Hiroyuki Kagi, Steven D’Hondt, Fumio Inagaki, Yuki Morono, Tatsuhiko Hoshino, Naotaka Tomioka & Motoo Ito in Communications Biology volume
Newly discovered single-celled creatures living deep beneath the seafloor have provided clues about how to find life on Mars. These bacteria were discovered living in tiny cracks inside volcanic rocks after researchers perfected a new method cutting rocks into ultrathin slices to study under a microscope. Researchers estimate that the rock cracks are home to a community of bacteria as dense as that of the human gut, about 10 billion bacterial cells per cubic centimeter.
The upper oceanic crust is mainly composed of basaltic lava that constitutes one of the largest habitable zones on Earth. However, the nature of deep microbial life in oceanic crust remains poorly understood, especially where old cold basaltic rock interacts with seawater beneath sediment. Researchers show that microbial cells are densely concentrated in Fe-rich smectite on fracture surfaces and veins in 33.5- and 104-million-year-old (Ma) subseafloor basaltic rock. The Fe-rich smectite is locally enriched in organic carbon. Nanoscale solid characterizations reveal the organic carbon to be microbial cells within the Fe-rich smectite, with cell densities locally exceeding 1010 cells/cm3. Dominance of heterotrophic bacteria indicated by analyses of DNA sequences and lipids supports the importance of organic matter as carbon and energy sources in subseafloor basalt. Given the prominence of basaltic lava on Earth and Mars, microbial life could be habitable where subsurface basaltic rocks interact with liquid water.
Multiwavelength Follow-up of the Hyperluminous Intermediate-mass Black Hole Candidate 3XMM J215022.4−055108
by Dacheng Lin, Jay Strader, Aaron J. Romanowsky, Jimmy A. Irwin, Olivier Godet6,7, Didier Barret, Natalie A. Webb, Jeroen Homan, and Ronald A. Remillard in The Astrophysical Journal Letters
Astronomers have found the best evidence for the perpetrator of a cosmic homicide: a black hole of an elusive class known as ‘intermediate-mass,’ which betrayed its existence by tearing apart a wayward star that passed too close.
Researchers recently discovered the X-ray/optical outbursting source 3XMM J215022.4−055108. It was best explained as the tidal disruption of a star by an intermediate-mass black hole of mass of a few tens of thousand solar masses in a massive star cluster at the outskirts of a large barred lenticular galaxy at D L = 247 Mpc. However, they could not completely rule out a Galactic cooling neutron star as an alternative explanation for the source. In order to further pin down the nature of the source, sientists have obtained new multiwavelength observations by XMM-Newton and the Hubble Space Telescope (HST). The optical counterpart to the source in the new HST image is marginally resolved, which rules out the Galactic cooling neutron star explanation for the source and suggests a star cluster of half-light radius ~27 pc. The new XMM-Newton observation indicates that the luminosity was decaying as expected for a tidal disruption event and that the disk was still in the thermal state with a supersoft X-ray spectrum. Therefore, the new observations confirm the source as one of the best intermediate-mass black hole candidates.
Close-Packed Nanowire-Bacteria Hybrids for Efficient Solar-Driven CO2 Fixation
by Yude Su, Stefano Cestellos-Blanco, Ji Min Kim, Hao Zhang, Yuhong Cao, Peidong Yang in Joule
Chemists have created a hybrid system of bacteria and nanowires that captures energy from sunlight and transfers it to the bacteria to turn carbon dioxide and water into organic molecules and oxygen. On Earth, such a biohybrid could remove carbon dioxide from the atmosphere. On Mars, it would provide colonists with raw material to manufacture organic compounds ranging from fuels to drugs. The efficiency is greater than the photosynthetic efficiency of most plants.
- Close-packed bacteria-nanowire hybrids achieved
- Microbial CO2-reducing current density boosted to 0.65 mA cm−2
- COMSOL simulation explains the nanowire-cell interactions under different pH conditions
- A 3.6% solar-to-acetate efficiency realized over 1 week
Microbial electro- and photo-electrochemical CO 2 fixation, in which CO 2-reducing microorganisms are directly interfaced with a cathode material, represent promising approaches for sustainable fuel production. Although considerable efforts have been invested to optimize microorganism species and electrode materials, the microorganism-cathode interface has not been systematically studied. Here, investigation of the interface allowed us to optimize the CO 2-reducing rate of silicon nanowire/ Sporomusa ovata system. Tuning the bulk electrolyte pH and increasing its buffering capacity supported the formation of a close-packed nanowire-bacteria cathode. Consequently, the resulting close-packed biohybrid achieved a CO 2-reducing current density of ∼0.65 mA cm −2. When coupled with a photovoltaic device, our system enabled solar-to-acetate production with ∼3.6% efficiency over 7 days.
Multiple early-formed water reservoirs in the interior of Mars
by Jessica J. Barnes, Francis M. McCubbin, Alison R. Santos, James M. D. Day, Jeremy W. Boyce, Susanne P. Schwenzer, Ulrich Ott, Ian A. Franchi, Scott Messenger, Mahesh Anand & Carl B. Agee in Nature Geoscience
Researchers probed Martian meteorites to reconstruct Mars’ chaotic history. Their findings suggest that Mars might not have had a global magma ocean.
The abundance and distribution of water within Mars through time plays a fundamental role in constraining its geological evolution and habitability. The isotopic composition of Martian hydrogen provides insights into the interplay between different water reservoirs on Mars. However, D/H (deuterium/hydrogen) ratios of Martian rocks and of the Martian atmosphere span a wide range of values. This has complicated identification of distinct water reservoirs in and on Mars within the confines of existing models that assume an isotopically homogenous mantle. Researchers present D/H data collected by secondary ion mass spectrometry for two Martian meteorites. These data indicate that the Martian crust has been characterized by a constant D/H ratio over the last 3.9 billion years. The crust represents a reservoir with a D/H ratio that is intermediate between at least two isotopically distinct primordial water reservoirs within the Martian mantle, sampled by partial melts from geochemically depleted and enriched mantle sources. From mixing calculations, they find that a subset of depleted Martian basalts are consistent with isotopically light hydrogen (low D/H) in their mantle source, whereas enriched shergottites sampled a mantle source containing heavy hydrogen (high D/H). They propose that the Martian mantle is chemically heterogeneous with multiple water reservoirs, indicating poor mixing within the mantle after accretion, differentiation, and its subsequent thermochemical evolution.
“These two different sources of water in Mars’ interior might be telling us something about the kinds of objects that were available to coalesce into the inner, rocky planets,” Barnes, an assistant professor of planetary sciences in the University of Arizona Lunar and Planetary Laboratory, said. Two distinct planetesimals with vastly different water contents could have collided and never fully mixed. “This context is also important for understanding the past habitability and astrobiology of Mars.”
ALMA 50-parsec-resolution Imaging of Jet–ISM Interaction in the Lensed Quasar MG J0414+0534
by Kaiki Taro Inoue, Satoki Matsushita, Kouichiro Nakanishi, and Takeo Minezaki in The Astrophysical Journal Letters
By combining the power of strong gravitational lensing with the capability of the Atacama Large Millimeter/submillimeter Array (ALMA), a team of astronomers from Japan and Taiwan imaged disturbed gaseous clouds in a distant quasar called MG J0414+0534; the researchers also found that the disruption is caused by supermassive black hole jets.
Researchers report their high-resolution (0farcs03–0farcs07) Atacama Large Millimeter/submillimeter Array (ALMA) imaging of the quadruply lensed radio-loud quasar MG J0414+0534 at redshift z = 2.639 in the continuum and the broad CO(11−10) line at ~340 GHz. With the help of strong lensing magnification and ALMA’s high resolution, they succeeded in resolving the jet/dust and CO gas in the quasar host galaxy, both extending up to ~1 kpc, with a resolution of ~50 pc for the first time. Both the continuum emission and the CO(11−10) line have a similar bimodal structure aligned with the quasar jets (~200 pc) observed by Very Long Baseline Interferometry at 5 and 8.4 GHz. The CO gas in the vicinity of both the eastern and western jet components at the location of ~80 pc from the quasar core are moving at high velocities, up to ±600 km s−1 relative to the core. The observed features show clear evidence of strong interaction between the jets and interstellar medium (ISM). High temperature and high-density environments in the ISM of the quasar host galaxy, as suggested from CO line ratios, also support this result. The small scale of the jets, the jet–ISM interaction, and the continuum spectral energy distribution of this source indicate that they are watching the infancy stage of quasar radio activity.
A 1201 s Orbital Period Detached Binary: the First Double Helium Core White Dwarf LISA Verification Binary
by Warren R. Brown, Mukremin Kilic, A. Bedard, Alekzander Kosakowski, P. Bergeron
Astronomers detect first double helium-core white dwarf gravitational wave source
Researchers report the discovery of a 1201 s orbital period binary, the third shortest-period detached binary known. SDSS J232230.20+050942.06 contains two He-core white dwarfs orbiting with a 27 deg inclination. Located 0.76 kpc from the Sun, the binary has an estimated LISA 4-yr signal-to-noise ratio of 40. J2322+0509 is the first He+He white dwarf LISA verification binary, a source class that is predicted to account for one-third of resolved LISA ultra-compact binary detections.
According to Dr Warren Brown, CfA astronomer and lead author on the study,
“We’re finding that the binaries that might be the hardest to detect may actually be the strongest sources of gravitational waves. This binary was difficult to detect because it is oriented face-on to us, like a bull’s eye, rather than edge-on. Remarkably, the binary’s gravitational waves are 2.5 times stronger at this orientation than if it were orientated edge-on like an eclipsing binary.”
The pair also held another surprise for researchers. With an orbital period of 1,201 seconds or just over 20 minutes, the pair is confirmed as having the third shortest period of all known detached binaries.
“This pair is at the extreme end of stars with short orbital periods,” said Brown. “And the orbit of this pair of objects is decaying. The gravitational waves that are being emitted are causing the pair to lose energy; in six or seven million years they will merge into a single, more-massive white dwarf.”
MISC
Margaret Burbidge, Astronomer Who Studied the Inner Workings of Stars, Dies at 100:
On This Day in Space: April 9, 1959: NASA introduces the ‘Mercury 7’ astronauts.
Astronomers Battle Space Explorers for Access to Moon’s Far Side: Without protection from radio interference, a giant observatory on the moon’s hidden hemisphere could prove unworkable.
Astronauts share isolation workout tips from space (video)
Preventing the contamination of other planets:
While the Covid-19 pandemic continues to develop rapidly the world’s knowledge of contamination is rising in parallel with the sale of hand sanitizer.
Large and small events have been cancelled globally and air-traffic is drifting to a standstill. The spread of the deadly virus has almost brought our busy planet to a halt.
The effect contamination can have on a planet is not just a recent important topic for consideration. In 1967 a treaty was drafted called ‘The Outer Space Treaty’. Now over 50 years old, the treaty has 109 signatory countries. It provides the basic framework on international space law. The treaty was a progressive step to make space travel a peaceful endeavour by stating ‘space and celestial bodies cannot be appropriated by a nation’. This means a country cannot claim the moon or any other planet as their own.
Abiding by the treaty each space mission must “avoid the harmful contamination” of celestial bodies. This is one reason why space crafts are often built, tested and prepared in ‘clean rooms’. Measured by particle count, there are different grades of decontamination to which a space mission must adhere to. This is mission-specific. For example, if a spacecraft were to land on Mars it would have more stringent decontamination procedures than a mission simply orbiting and not touching the surface of the Red Planet.
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