probably the oldest (launched in 1967) confirmed still functioning satellite, LES 5
Milky Way stabilized shows the Earth is spinning through space
Something is Lurking in the Heart of Quasar 3C 279
One year ago, the Event Horizon Telescope (EHT) Collaboration published
the first image of a black hole in the nearby radio galaxy M 87. Now the
collaboration has extracted new information from the EHT data on the
distant quasar 3C 279: they observed the finest detail ever seen in a
jet produced by a supermassive black hole. New analyses, led by
Jae-Young Kim from the Max Planck Institute for Radio Astronomy (MPIfR)
in Bonn, enabled the collaboration to trace the jet back to its launch
point, close to where violently variable radiation from across the
electromagnetic spectrum arises.
Hubble Finds Best Evidence for Elusive Mid-Size Black Hole
Intermediate-mass black holes (IMBHs) are a long-sought “missing link” in black hole evolution. There have been a few other IMBH candidates found to date. They are smaller than the supermassive black holes that lie at the cores of large galaxies, but larger than stellar-mass black holes formed by the collapse of massive stars. This new black hole is over 50 000 times the mass of our Sun.
IMBHs are hard to find. “Intermediate-mass black holes are very elusive objects, and so it is critical to carefully consider and rule out alternative explanations for each candidate. That is what Hubble has allowed us to do for our candidate,” said Dacheng Lin of the University of New Hampshire, principal investigator of the study.
Possible fragmentation of interstellar comet 2I/Borisov
Images obtained by HST/WFC3 GO programs 16041 (PI Jewitt; ATEL #13611)
and 16040 (PI Bolin) on 2020 March 23 and 28 indicate the presence of a
small fragment separated by ~0.3 arcsec in the anti-solar direction,
west of north, from the coma’s optocenter in addition to the bimodal
appearance described by Jewitt et al. ATEL #13611.
The distance between the optocenter and the fragment changes by 1-2
pixels (0.0395 arcsec/pixel) between the 2020 March 23 and 2020 March 28
observation dates. This implies a lower limit on the relative velocity
between the nucleus and the fragment due to projection effects of at
least ~0.5 m/s, consistent with the escape velocity from a sub km-scale
radius body. The angular separation and motion detected in the 2020
March 23 and 28 data are consistent with a release date in 2020 March 7
around the time of the comet’s ~0.7 mag outburst observed by
ground-based facilities (Drahus et al. ATel #13549., Jehin et al. 2020, CBET 4729).
The fragment is not seen in the most recent HST/WFC3 data taken on 2020
February 24 (GO 16041, PI Jewitt) which were acquired before the
comet’s outburst. The fragment has an estimated upper size limit of
<100 m, assuming a geometric albedo of 0.04, and is confirmed in
HST/WFC3 2020 March 30 data taken by HST GO 16087, PI Jewitt. In
addition, the post-outburst HST/WFC3 images show the existence of two
new jets with position angles of 240 and 310 degrees not observed in
previous HST/WFC3 images (Bolin 2020, arxiv:1912.07386).
Comet C/2019 Y4 ATLAS 27 03 2020
Scientists Trace Neutron Star Crash That Helped Form Our Solar System
Astronomers are on the hunt for the remnants of the neutron-star collision that gave Earth its precious metals.
When neutron stars merge, they spew a wealth of short-lived elements into their surroundings, and these materials become part of later-forming solar systems. Now scientists are trying to close in on the merger that seeded our solar system by tracing the elements produced by the original decaying material. From that work, they believe the responsible merger occurred 100 million years before and 1,000 light-years away from the birth of our solar system.
“It was close,” the project’s lead scientist, Szabolcs Marka, who is a physicist at Columbia University, told Space.com. “If you look up at the sky and you see a neutron-star merger 1,000 light-years away, it would outshine the entire night sky.”
Marka and his colleague Imre Bartos, an astrophysicist at the University of Florida, used meteorites from the dawn of the solar system to track down the collision. They analyzed the isotopes—flavors of elements with different numbers of neutrons in their atoms—in these rocks.
Japan’s asteroid-smashing probe reveals a surprisingly young space rock
A cannonball that a Japanese spacecraft fired at an asteroid is shedding light on the most common type of asteroid in the solar system, a new study reports.
Carbonaceous, or C-type, space rocks make up about three-quarters of known asteroids. Previous research suggests that they are relics of the early solar system that contain troves of primordial material from the nebula that gave birth to the sun and its planets about 4.6 billion years ago. This makes research into these carbon-rich asteroids essential to understanding planetary formation.
To learn more about C-type asteroids, the Japan Aerospace Exploration Agency (JAXA) deployed the spacecraft Hayabusa2 to Ryugu, a 2,790-foot-wide (850 meters) near-Earth asteroid that is one of the darkest celestial bodies in the solar system. The C-type asteroid’s name, which means “dragon palace,” refers to a magical underwater castle from a Japanese folk tale.
Microbiological and Nutritional Analysis of Lettuce Crops Grown on the International Space Station
The ability to grow safe, fresh food to supplement packaged foods of astronauts in space has been an important goal for NASA. Food crops grown in space experience different environmental conditions than plants grown on Earth (e.g., reduced gravity, elevated radiation levels). To study the effects of space conditions, red romaine lettuce, Lactuca sativa cv ‘Outredgeous,’ plants were grown in Veggie plant growth chambers on the International Space Station (ISS) and compared with ground-grown plants. Multiple plantings were grown on ISS and harvested using either a single, final harvest, or sequential harvests in which several mature leaves were removed from the plants at weekly intervals. Ground controls were grown simultaneously with a 24–72 h delay using ISS environmental data. Food safety of the plants was determined by heterotrophic plate counts for bacteria and fungi, as well as isolate identification using samples taken from the leaves and roots. Molecular characterization was conducted using Next Generation Sequencing (NGS) to provide taxonomic composition and phylogenetic structure of the community. Leaves were also analyzed for elemental composition, as well as levels of phenolics, anthocyanins, and Oxygen Radical Absorbance Capacity (ORAC). Comparison of flight and ground tissues showed some differences in total counts for bacteria and yeast/molds (2.14 – 4.86 log10 CFU/g), while screening for select human pathogens yielded negative results. Bacterial and fungal isolate identification and community characterization indicated variation in the diversity of genera between leaf and root tissue with diversity being higher in root tissue, and included differences in the dominant genera. The only difference between ground and flight experiments was seen in the third experiment, VEG-03A, with significant differences in the genera from leaf tissue. Flight and ground tissue showed differences in Fe, K, Na, P, S, and Zn content and total phenolic levels, but no differences in anthocyanin and ORAC levels. This study indicated that leafy vegetable crops can produce safe, edible, fresh food to supplement to the astronauts’ diet, and provide baseline data for continual operation of the Veggie plant growth units on ISS.
Born in Germany in an era when no woman could obtain a formal education in science anywhere in the world, Maria Clara Eimmart (May 27, 1676–October 29, 1707) predated Caroline Herschel
— the world’s first professional woman astronomer — by a century. She
went on to become an artist, engraver, and astronomer who produced some
of the most striking astronomical art since the invention of the
telescope, in a time when humanity had no idea that the universe
contained galaxies other than our own.
The golden age of neutron-star physics has arrived
When a massive star dies in a supernova, the explosion is only the beginning of the end. Most of the stellar matter is thrown far and wide, but the star’s iron-filled heart remains behind. This core packs as much mass as two Suns and quickly shrinks to a sphere that would span the length of Manhattan. Crushing internal pressure — enough to squeeze Mount Everest to the size of a sugar cube — fuses subatomic protons and electrons into neutrons.
Astronomers know that much about how neutron stars are born. Yet exactly what happens afterwards, inside these ultra-dense cores, remains a mystery. Some researchers theorize that neutrons might dominate all the way down to the centre. Others hypothesize that the incredible pressure compacts the material into more exotic particles or states that squish and deform in unusual ways.
Now, after decades of speculation, researchers are getting closer to solving the enigma, in part thanks to an instrument on the International Space Station called the Neutron Star Interior Composition Explorer (NICER).
kreuzaderny