Soviet postcard commemorating Strelka and Belka, the first dogs to enter space and return to Earth safely (1961).
Strelka (Стрелка) and Belka (Белка) spent a day in space aboard Sputnik 5 on 19 August 1960 before safely returning to Earth.
A new black hole image reveals the behemoth’s magnetic fields
Astronomers have gotten their first glimpse of the magnetic fields tangled around a black hole.
The Event Horizon Telescope has unveiled the magnetism of the hot, glowing gas around the supermassive black hole at the heart of galaxy M87, researchers report in two studies published online March 24 in the Astrophysical Journal Letters. These magnetic fields are thought to play a crucial role in how the black hole scarfs down matter and launches powerful plasma jets thousands of light-years into space (SN: 3/29/19).
“We’ve known for decades that jets are in some sense powered by accretion onto supermassive black holes, and that the in-spiraling gas and the outflowing plasma are highly magnetized — but there was a lot of uncertainty in the exact details,” says Eileen Meyer, an astrophysicist at the University of Maryland, Baltimore County not involved in the work. “The magnetic field structure of the plasma near the event horizon [of a black hole] is a completely new piece of information.”
Astronomers spy a nearby, blazing hot super-Earth
Super-Earth exoplanets are defined as being larger and more massive than Earth, but smaller and less massive than Neptune (about 17 times Earth’s mass). Some super-Earths orbit near their stars and are likely too hot for life. Others orbit farther out and so would be more temperate, in some cases potentially habitable. Hot super-Earths, if too close to their stars, are thought to be prone to losing their atmospheres. Super-Earths with atmospheres can be challenging to study, too. That’s why astronomers with the CARMENES consortium in Europe are excited today (March 4, 2021) to announce the discovery of a hot super-Earth, with an atmosphere, orbiting a nearby star!
The star is Gliese 486, a red dwarf only 24 light-years away. The exoplanet is called Gliese 486b. It does appear to retain its atmosphere, despite its close orbit around its star.
This blazing hot super-Earth – with an atmosphere – is therefore an ideal target for future telescopes and for testing different scientific models depicting rocky exoplanet atmospheres.
astronauts collect leaf samples from plants growing aboard the ISS
Parker Solar Probe’s WISPR instrument, short for Wide-field Imager for
Parker Solar Probe, detected a bright rim around the edge of the planet
that may be nightglow — light emitted by oxygen atoms high in the
atmosphere that recombine into molecules in the nightside. The prominent
dark feature in the center of the image is Aphrodite Terra, the largest
highland region on the Venusian surface. Bright streaks in WISPR, such
as the ones seen here, are typically caused by a combination of charged
particles — called cosmic rays — sunlight reflected by grains of space
dust, and particles of material expelled from the spacecraft’s
structures after impact with those dust grains. The number of streaks
varies along the orbit or when the spacecraft is traveling at different
speeds, and scientists are still in discussion about the specific
origins of the streaks here. The dark spot appearing on the lower
portion of Venus is an artifact from the WISPR instrument. Credits:
NASA/Johns Hopkins APL/Naval Research Laboratory/Guillermo Stenborg and
Brendan Gallagher
A space hurricane over the Earth’s polar ionosphere
In Earth’s low atmosphere, hurricanes are destructive due to their great
size, strong spiral winds with shears, and intense rain/precipitation.
However, disturbances resembling hurricanes have not been detected in
Earth’s upper atmosphere. Here, we report a long-lasting space hurricane
in the polar ionosphere and magnetosphere during low solar and
otherwise low geomagnetic activity. This hurricane shows strong circular
horizontal plasma flow with shears, a nearly zero-flow center, and a
coincident cyclone-shaped aurora caused by strong electron precipitation
associated with intense upward magnetic field-aligned currents. Near
the center, precipitating electrons were substantially accelerated to
~10 keV. The hurricane imparted large energy and momentum deposition
into the ionosphere despite otherwise extremely quiet conditions. The
observations and simulations reveal that the space hurricane is
generated by steady high-latitude lobe magnetic reconnection and current
continuity during a several hour period of northward interplanetary
magnetic field and very low solar wind density and speed.
Low Radio Frequency Observations from the Moon Enabled by NASA Landed Payload Missions
A new era of exploration of the low radio frequency Universe from the Moon will soon be underway with landed payload missions facilitated by NASA’s Commercial Lunar Payload Services (CLPS) program. CLPS landers are scheduled to deliver two radio science experiments, ROLSES to the nearside and LuSEE to the farside, beginning in 2021. These instruments would be pathfinders for a 10-km diameter interferometric array, FARSIDE, composed of 128 pairs of dipole antennas proposed to be delivered to the lunar surface later in the decade. ROLSES and LuSEE, operating at frequencies from 100 kHz to a few tens of MHz, will investigate the plasma environment above the lunar surface and measure the fidelity of radio spectra on the surface. Both use electrically-short, spiral-tube deployable antennas and radio spectrometers based upon previous flight models. ROLSES will measure the photoelectron sheath density to better understand the charging of the lunar surface via photoionization and impacts from the solar wind, charged dust, and current anthropogenic radio frequency interference. LuSEE will measure the local magnetic field and exo-ionospheric density, interplanetary radio bursts, Jovian and terrestrial natural radio emission, and the galactic synchrotron spectrum. FARSIDE, and its precursor risk-reduction six antenna-node array PRIME, would be the first radio interferometers on the Moon. FARSIDE would break new ground by imaging radio emission from Coronal Mass Ejections (CME) beyond 2 solar radii, monitor auroral radiation from the B-fields of Uranus and Neptune (not observed since Voyager), and detect radio emission from stellar CMEs and the magnetic fields of nearby potentially habitable exoplanets.
Atomically Precise Sensors Could Detect Another Earth
Gazing into the dark and seemingly endless night sky above, people have long wondered: Is there another world like ours out there, somewhere? Thanks to new sensors that we and other astronomers are developing, our generation may be the first to get an affirmative answer—and the earliest hints of another Earth could come as soon as this year.
Astronomers have discovered thousands of exoplanets so far, and almost two dozen of them are roughly the size of our own planet and orbiting within the so-called habitable zone of their stars, where water might exist on the surface in liquid form. But none of those planets has been confirmed to be rocky, like Earth, and to circle a star like the sun. Still, there is every reason to expect that astronomers will yet detect such a planet in a nearby portion of the galaxy.
So why haven’t they found it yet? We can sum up the difficulty in three words: resolution, contrast, and mass. Imagine trying to spot Earth from hundreds of light-years away. You would need a giant telescope to resolve such a tiny blue dot sitting a mere 150 million kilometers (0.000016 light-year) from the sun. And Earth, at less than a billionth the brightness of the sun, would be hopelessly lost in the glare.
Perseverance’s Eyes See a Different Mars
The rover is studded with a couple dozen cameras—25, if you count the two on the drone helicopter. Most of them help the vehicle drive safely. A few peer closely and intensely at ancient Martian rocks and sands, hunting for signs that something once lived there. Some of the cameras see colors and textures almost exactly the way the people who built them do. But they also see more. And less. The rover’s cameras imagine colors beyond the ones that human eyes and brains can come up with. And yet human brains still have to make sense of the pictures they send home.
To find hints of life, you have to go to a place that was once likely livable. In this case that’s Jezero Crater. Three or four billion years ago, it was a shallow lake with sediments streaming down its walls. Today those are cliffs 150 feet tall, striated and multicolored by those sediments spreading and drying across the ancient delta.
Those colors are a geological infographic. They represent time, laid down in layers, stratum after stratum, epoch after epoch. And they represent chemistry. NASA scientists pointing cameras at them—the right kind of cameras—will be able to tell what minerals they’re looking at, and maybe whether wee Martian beasties once called those sediments home. “If there are sedimentary rocks on Mars that preserve evidence of any ancient biosphere, this is where we’re going to find them,” says Jim Bell, a planetary scientist at Arizona State University and the principal investigator on one of the rover’s sets of eyes. “This is where they should be.”
Astronomers Confirm Solar System’s Most Distant Known Object Is Indeed Farfarout
With the help of the international Gemini Observatory, a Program of NSF’s NOIRLab, and other ground-based telescopes, astronomers have confirmed that a faint object discovered in 2018 and nicknamed “Farfarout” is indeed the most distant object yet found in our Solar System. The object has just received its designation from the International Astronomical Union.
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