Galaxies are not static islands of stars – they are dynamic and ever-changing, constantly on the move through the darkness of the Universe. Sometimes, as seen in this spectacular Hubble image of Arp 256, galaxies can collide in a crash of cosmic proportions.
The organic and intricate features of a volcanic cave come alive in great detail in this three-dimensional image of La Cueva de Los Verdes in Lanzarote, Spain. Some of the most innovative scanning technologies have produced the largest 3D scan of a lava tube on Earth.Lava tubes are planetary caves. Similar cave systems have been found from orbit on the Moon and Mars. These underground formations could one day provide safe habitats for humans on other celestial bodies – they provide constant temperature and a good shelter against cosmic radiation and micrometeorites.Understanding the origins and formation of these caves on Earth is a passage for simulating the future of planetary explorers across the Solar System. A team of speleologists from the University of Padova, Italy mapped the main path of the cave system aided by ESA astronaut Matthias Mauer. The image covers a 1.3 km section of the lava tube with an unprecedented resolution of few centimetres.
Three more of the mysterious fast radio burst (FRB) signals have been detected this month, and one of them is a real record-breaker, coming in with the highest signal-to-noise ratio ever recorded. That makes it the "brightest" FRB that's ever been observed.The signals came in on March 1, March 9 (that's the really bright one) and March 11, snagged by the Parkes Observatory radio telescope in remote Australia.They are called FRB 180301, FRB 180309 and FRB 180311, following the fast radio burst convention of being named for the dates on which they occurred.
Yale University astronomers have developed a powerful new spectrometer to search for Earth-size planets around nearby stars. Expected to improve precision over earlier ground-based instruments by a factor of 10, the Extreme Precision Spectrometer – EXPRES – is now in operation at the Lowell Observatory’s Discovery Channel Telescope in Arizona.
This thread might be interesting if you’ve ever wondered: “Could the govt be hiding knowledge of a killer asteroid from us?” Answer is no: we’d all be talking about it on Twitter. (Thread is about worrisome object that, with more data, turned out NOT to be a threat.)
NASA has changed its mind and will allow proposals for its next Discovery competition to use RTGs, according to an email sent late yesterday:
Didn’t want to start a new thread yet for this news.https://twitter.com/jeff_foust/status/975410163481022464?s=20QuoteNASA has changed its mind and will allow proposals for its next Discovery competition to use RTGs, according to an email sent late yesterday:
Ceres turns out to be a livelier place than we might have imagined. Continuing analysis of data from the Dawn spacecraft is showing us an object where surface changes evidently caused by temperature variations induced by the dwarf planet’s orbit are readily visible even in short time frames. Two new papers on the Dawn data are now out in Science Advances, suggesting variations in the amount of surface ice as well as newly exposed crustal material.
We identify a sub-Neptune exoplanet (Rp=2.5±0.2 R⊕) transiting a solar twin in the Ruprecht 147 star cluster (3 Gyr, 300 pc, [Fe/H] = +0.1 dex). The ~81 day light curve for EPIC 219800881 (V = 12.71) from K2 Campaign 7 shows six transits with a period of 13.84 days, a depth of ~0.06%, and a duration of ~4 hours. Based on our analysis of high-resolution MIKE spectra, broadband optical and NIR photometry, the cluster parallax and interstellar reddening, and isochrone models from PARSEC, Dartmouth, and MIST, we estimate the following properties for the host star: M⋆=1.01±0.03 M⊙, R⋆=0.95±0.03 R⊙, and Teff=5695±50 K. This star appears to be single, based on our modeling of the photometry, the low radial velocity variability measured over nearly ten years, and Keck/NIRC2 adaptive optics imaging and aperture-masking interferometry. Applying a probabilistic mass-radius relation, we estimate that the mass of this planet is Mp=7+5−3 M⊕, which would cause a RV semi-amplitude of K=2±1 m s−1 that may be measurable with existing precise RV facilities. After statistically validating this planet with BLENDER, we now designate it K2-231 b, making it the second sub-stellar object to be discovered in Ruprecht 147 and the first planet; it joins the small but growing ranks of 23 other planets found in open clusters.
About 70,000 years ago, during human occupation of the planet, a small, reddish star approached our solar system and gravitationally disturbed comets and asteroids. Astronomers from the Complutense University of Madrid and the University of Cambridge have verified that the movement of some of these objects is still marked by that stellar encounter.
Now, two astronomers from the Complutense University of Madrid, the brothers Carlos and Raúl de la Fuente Marcos, together with the researcher Sverre J. Aarseth of the University of Cambridge (United Kingdom), have analyzed for the first time nearly 340 solar system objects with hyperbolic orbits (very open V-shaped, rather than elliptical) They have concluded that the trajectories of some of these were influenced by the passage of Scholz's star."Using numerical simulations, we have calculated the radiants or positions in the sky from which all these hyperbolic objects seem to come," explains Carlos de la Fuente Marcos, a co-author of the study now published in Monthly Notices of the Royal Astronomical Society."In principle," he adds, "one would expect those positions to be evenly distributed in the sky, particularly if these objects come from the Oort cloud. However, what we find is very different—a statistically significant accumulation of radiants. The pronounced over-density appears projected in the direction of the constellation of Gemini, which fits the close encounter with Scholz's star."
Scholz's star is actually a binary system formed by a small red dwarf with about 9 percent of the mass of the sun, around which a much less bright and smaller brown dwarf orbits. It is likely that human ancestors saw its faint reddish light during prehistorical nights.
QuoteScholz's star is actually a binary system formed by a small red dwarf with about 9 percent of the mass of the sun, around which a much less bright and smaller brown dwarf orbits. It is likely that human ancestors saw its faint reddish light during prehistorical nights.https://phys.org/news/2018-03-evidence-star-disturbed-prehistory-solar.amp
Evidence that a star disturbed prehistory solar system comets
Quote from: Star One on 03/21/2018 08:28 pmQuoteScholz's star is actually a binary system formed by a small red dwarf with about 9 percent of the mass of the sun, around which a much less bright and smaller brown dwarf orbits. It is likely that human ancestors saw its faint reddish light during prehistorical nights.https://phys.org/news/2018-03-evidence-star-disturbed-prehistory-solar.ampOnly if human ancestors had much more sensitive eyes than we do. Even at its closest approach the star would have been fainter than 10th magnitude.
All the articles I’ve seen about this have reported the same thing so I assume it had come from an official press release somewhere?
As I read this, the only thing that might have been visible are the (potential) occasional flares.
Scholz’s Star is a binary system, a red dwarf orbited by a brown dwarf, and it is likely that there was a time when our ancestors could see it in the sky. But only barely — Eric Mamajek has pointed out that even at its closest approach, the apparent magnitude would have been in the range of 11.4, which is five magnitudes fainter than what the naked eye can see, even in the pristine skies of paleolithic Earth. What might have been visible would have been flares from the M-dwarf, which could have created short-lived transient events, fleeting but noticeable.