Tuesday, February 21, 2017

Experiments Call Origin of Earth's Iron into Question

An infographic describing three theories on how the Earth got its iron signature.Designed by Laura Martin/The University of Texas at Austin Jackson School of Geosciences. Images 1 and 2 from NASA/JPL-Caltech, Image 3 from X-Science, Earth from NASA/JPL.

New research from The University of Texas at Austin reveals that the Earth’s unique iron composition isn’t linked to the formation of the planet’s core, calling into question a prevailing theory about the events that shaped our planet during its earliest years.

Astrophysicists Study Surprising Changes in the Appearance of a Supermassive Black Hole

2.4 arcmin wide closeup of NGC 2617

Members of the Sternberg Astronomical Institute of the Lomonosov Moscow State University have been studying changes in the appearance of emission from around the supermassive black hole in the center of a galaxy known to astronomers as NGC 2617. The center of this galaxy, underwent dramatic changes in its appearance several years ago: it became much brighter and things that had not been seen before were seen. This sort of dramatic change can give us valuable information for understanding what the surroundings of a giant black hole are like and what is going on near the black hole. The results of these investigations have been published in the Monthly Notices of the Royal Astronomical Society, one of the world's top-rated astronomical journals.

'Gravitational Noise' Interferes with Determining the Coordinates of Distant Sources

A map showing the characteristic values of the “jittering” of source coordinates around their true position caused by the Galaxy’s “gravitational noise”, in microarcseconds (shown in contours) for a ten-years observation period. The crosses represent the positions of ICRF reference sources. Credit: mipt.ru

Our Galaxy’s gravitational field limits the accuracy of astrometric observations of distant objects. This is most clearly appeared for objects that are visually located behind the central regions of the Galaxy and the Galactic plane, where the deviation can be up to several dozen microarcseconds. And, more importantly, the effect of this gravitational “noise” cannot be removed. This means that at a certain moment it will no longer be possible to improve the accuracy of determining the position of reference objects, which are used to define the coordinates of all other sources. The results of the study have been published in The Astrophysical Journal.

New Data About Two Distant Asteroids Give a Clue to the Possible 'Planet Nine'

Sequence of images taken with the Gran Telescopio CANARIAS (GTC) to identify one of the ETNO´s studied in this article, 2013 RF98, where one can see how it moves during four consecutive nights. Below, right, visible spectra obtained with the GTC of the two objects 2004 VN112 and 2013 RF98. The red lines show the gradients of the spectra. Credit: Julia de León (IAC).

In the year 2000 the first of a new class of distant solar system objects was discovered, orbiting the Sun at a distance greater than that of Neptune: the extreme trans Neptunian objects (ETNOs). Their orbits are very far from the Sun compared with that of the Earth. We orbit the Sun at a mean distance of one astronomical unit (1 AU which is 150 million kilometers) but the ETNOs orbit at more than 150 AU. To give an idea of how far away they are, Pluto’s orbit is at around 40 AU and its closest approach to the Sun (perihelion) is at 30 AU. This discovery marked a turning point in Solar System studies, and up to now, a total of 21 ETNOs have been identified.

Origin of Spooky Meteor Noises Reappraised by Researchers

Sandia National Laboratories researcher Richard Spalding, recently deceased, examines the sky through which meteors travel. (Photo by Randy Montoya)

When a meteor is about to conk your neighborhood and gives fair warning by emitting sizzling, rustling and hissing sounds as it descends, you might think that the universe is being sporting. But these auditory warnings, which do occur, seem contrary to the laws of physics if they are caused by the friction of the fast-moving meteor or asteroid plunging into Earth’s atmosphere. Because sound travels far slower than light, the sounds should arrive several minutes after the meteor hits, rather than accompany or even precede it.

Monday, February 20, 2017

New Legal Powers Could Send British Scientists into Space to Conduct Zero-Gravity Medical Experiments

Spaceports, like this artist's rendition, could soon be operational all around the UK. Credit: SWNS.com

British scientists will be able to fly to the edge of space to conduct vital medical experiments under new powers unveiled this week. Laws paving the way for spaceports in the UK will allow ‎experiments to be conducted in zero gravity which could help develop medicines. The powers will allow the launch of satellites from the UK for the first time, horizontal flights to the edge of space for scientific experiments and the establishment and operation of spaceports in regions across the UK.

The Thread of Star Birth

Star formation on filaments in RCW106. Credit: ESA/Herschel/PACS, SPIRE/Hi-GAL Project. Acknowledgement: UNIMAP / L. Piazzo, La Sapienza – Università di Roma; E. Schisano / G. Li Causi, IAPS/INAF, Italy

Stars are bursting into life all over this image from ESA’s Herschel space observatory. It depicts the giant molecular cloud RCW106, a massive billow of gas and dust almost 12 000 light-years away in the southern constellation of Norma, the Carpenter's Square. Cosmic dust, a minor but crucial ingredient in the interstellar material that pervades our Milky Way galaxy, shines brightly at infrared wavelengths. By tracing the glow of dust with the infrared eye of Herschel, astronomers can explore stellar nurseries in great detail.