For decades, astronomers have speculated that there may be water on the Moon. In recent years, this speculation was confirmed one orbiting satellite after another detected water ice around the Moon’s southern polar region. Within this part of the lunar surface, known as the South-Pole Aitken Basin, water ice is able to persist because of the many permanently-shadowed craters that are located there.
But until now, scientists were operating under the assumption that lunar water was only to be found in permanently shadowed craters. But thanks to NASA’s Stratospheric Observatory for Infrared Astronomy (SOFIA), water has been observed on the sunlit side of the Moon for the first time. This discovery indicates that water may be distributed all across the lunar surface, and not limited to the dark corners.
Artist's illustration of a galaxy in the early universe that is very dusty and shows the first signs of a rotationally supported disk. In this image, the red color represents gas, and blue/brown represents dust as seen in radio waves with ALMA. Many other galaxies are visible in the background, based on optical data from VLT and Subaru.
Credit: B. Saxton NRAO/AUI/NSF, ESO, NASA/STScI; NAOJ/Subaru
The behaviour of galaxies in the early Universe attracts a lot of attention from researchers. In fact, everything about the early Universe is under intense scientific scrutiny for obvious reasons. But unlike the Universe’s first stars, which have all died long ago, the galaxies we see around us—including our own—have been here since the early days.
Current scientific thinking says that in the early days of the Universe, the galaxies grew slowly, taking billions of years to become what they are now. But new observations show that might not be the case.
One of six new spooky posters from NASA’s Galaxy of Horrors. Credit NASA-JPL/Caltech
While ghouls and goblins may provide the ghastly delights many of us associate with this time of year, NASA has just released a series of spooky space-themed posters that are more unearthly than any monsters or scary stories told around terrestrial campfires. This year for Halloween, the space agency has released a series of spine-tingling posters called Galaxy of Horrors. The terrifying destinations highlighted within are all based on real locations in the Universe.
Artist rendering of colliding neutron stars. Credit: Robin Dienel/Carnegie Institution for Science
Neutron stars are the remnants of massive stars that explode as supernovae at the end of their fusion lives. They’re super-dense cores where all of the protons and electrons are crushed into neutrons by the overpowering gravity of the dead star. They’re the smallest and densest stellar objects, except for black holes, and possibly other arcane, hypothetical objects like quark stars.
When two neutron stars merge, we can detect the resulting gravitational waves. But some aspects of these mergers are poorly-understood. One question surrounds short-lived gamma-ray bursts from these mergers. Previous studies have shown that these bursts may come from the decay of heavy elements produced in a neutron star merger.
A new study strengthens our understanding of these complex mergers and introduces a model that explains the gamma rays.
IRS 63 Circumstellar Disk C. ALMA/ Segura-Cox et al. 2020
Unless you’re reading this in an aircraft or the International Space Station, then you’re currently residing on the surface of a planet. You’re here because the planet is here. But how did the planet get here? Like a rolling snowball picking up more snow, planets form from loose dust and gas surrounding young stars. As the planets orbit, their gravity draws in more of the lose material and they grow in mass. We’re not certain when the process of planet formation begins in orbit of new stars, but we have incredible new insights from one of the youngest solar systems ever observed called IRS 63.
The Rho Ophiuchi cloud complex is a nebula of gas and dust that is located in the constellation Ophiuchus. It is one of the closest star-forming regions to the Solar System and where the young star system IRS 63 was observed
Primordial Soup
Swirling in orbit of young stars (or protostars) are massive disks of dust and gas called circumstellar disks. These disks are dense enough to be opaque hiding young solar systems from visible light. However, energy emanating from the protostar heats the dust which then glows in infrared radiation which more easily penetrates obstructions than wavelengths of visible light. In fact, the degree to which a newly forming star system is observed in either visible or infrared light determines its classification. Class 0 protostars are completely enshrouded and can only be observed in submillimeter wavelengths corresponding to far-infrared and microwave light. Class I protostars, are observable in the far-infrared, Class II in near-infrared/red, and finally a Class III protostar’s surface and solar system can be observed in visible light as the remaining dust and gas is either blown away by the increasing energy of the star AND/OR has formed into PLANETS! That’s where we came from. That leftover material orbiting newly forming stars is what accumulates to form US. The whole process from Class 0 to Class III, when the solar system leaves its cocoon of dust and joins the galaxy, is about 10 million years. But at what stage does planet formation begin? The youngest circumstellar disks we’d observed are a million years old and had shown evidence that planetary formation had already begun. The recently observed IRS 63 is less than 500,000 years old – Class I – and shows signs of possible planet formation. The excitement? We were surprised to see evidence of planetary formation so early in the life of a solar system.
The final Blue Moon of the decade this weekend rounds out October 2020.
Halloween. It’s not only a great time to dress up in ghoulish garb going from house to house, but a great time for some (in 2020, socially-distanced) sidewalk astronomy. This year also offers up a special trick-or-treat event, as the second Full Moon of October falls on the very last day of the month.
One of the Daya Bay detectors.
Roy Kaltschmidt, Lawrence Berkeley National Laboratory
When giant stars die in impressive supernova blasts, about 99% of the energy released goes into producing a flood of neutrinos. These tiny, ghostly particles slip through tons of matter like it’s not even there. But a new generation of detectors will be able to catch them, telling us of the inner machinations of the deaths of stars.
Accroding to new research, the Milky Way may still bear the marks of "ancient impacts". Credit: NASA/Serge Brunier
A team of researchers has discovered a complex network of filamentary structures in the Milky Way. The structures are made of atomic hydrogen gas. And we all know that stars are made mostly of hydrogen gas.
Not only is all that hydrogen potential future star-stuff, the team found that its filamentary structure is also a historical imprint of some of the goings-on in the Milky Way.
The Karl Jansky Very Large Array at night, with the Milky Way visible in the sky. Credit: NRAO/AUI/NSF; J. Hellerman
In 2005 astronomers found a dense grouping of stars in the Virgo constellation. It looked like a star cluster, except further surveys showed that some of the stars are moving towards us, and some are moving away. That finding was unexpected and suggested the Stream was no simple star cluster.
A 2019 study showed that the grouping of stars is no star cluster at all; instead, it’s the hollowed-out shell of a dwarf spheroidal galaxy that merged with the Milky Way. It’s called the Virgo Overdensity (VOD) or the Virgo Stellar Stream.
A new study involving some of the same researchers shows how and when the merger occurred and identifies other shells from the same merger.
Two more comets – 88P Howell and M3 ATLAS – are worth scouting the sky for into November 2020.
If you’re like us, you’ve been at taking advantage of every clear night during quarantine to get out and observe the night sky. Thankfully, 2020 has thus far been a ‘comet year,’ with a steady string of binocular comets, led by bright comet C/2020 F3 NEOWISE this summer. Fall is seeing another surge in comets topping +10th magnitude. Late October sees a brief dawn apparition of Comet C/2020 P1 NEOWISE and now, two other comets grace the dawn and dusk skies.
