Astronomy news

Asteroids and Meteors

At https://phys.org/news/2019-07-asteroid-earth.html ... Hat tip to William. An asteroid buzzed the earth and was barely noticed. It was 100m across and passed just 70,000 km away, last Thursday. The lack of warning shows how quickly potentially dangerous asteroids can cross the orbit of the earth. Astronomers have become adept at seeing asteroids at night - but not always so during daylight hours. The 2013 Chelyabinsk meteor was a case in point. It came from the direction of the sun (and was obscured by sunlight) - and nobody knew about it until it entered the atmosphere.

Einstein Question

At https://phys.org/news/2019-07-einstein-relativity-theory.html ... we seem to have two camps on Einstein and Relativity. The bigger group of scientists actively do research in order to sustain the theory (as that was what they were taught in their youth). The second, and smaller group seem to be constantly telling us Einstein's theory is about to tumble. In this latest study we are told Einstein's theory of Relativity is fraying at the edges. It is an interesting idea as the basis of their argument revolves around black holes - and the assumption mainstream is right about them.

Expansion of the Universe

At https://phys.org/news/2019-07-fast-radio-field-astronomy.html ... we have mysterious radio bursts - first discovered in 2007. Since then 100 or so have been announced - fast and bright flashes of radio waves issuing from space. What they are has yet to be determined.

Hayabasa2 Probe

At https://phys.org/news/2019-07-japan-hayabasa2-probe-touchdown-asteroid.html .... and https://phys.org/news/2019-07-japan-asteroid-probe-hayabasa2-touchdown.html ... the Japanese Hayabasa 2 space probe made a 'perfect' touchdown on asteroid Ryugu and has collected samples from beneath the surface for laboratory analysis. An incredible technological feat but we shall have to wait for the results of the analyses.

Solar cycle 25

At http://spaceweather.com (2nd July 2019) ... the face of the Sun has been blank for several days but on Sunday a small sun spot appeared, the beginnings of solar cycle 25. The solar minimum is still ongoing but the sun spot is a sign that it is coming to an end. The polarity of the sun spot is affected by its magnetic field. Sun spots switch polarity from one solar cycle to the next one, which is how they can tell it is cycle 25.

Another meteor making noises

A small asteroid exploded in the atmosphere near Peurto Rico on June 22nd - see http://spaceweather.com (June 25th 2019). It occurred in broad daylight and the airwaves produced were detected by the Nuclear Test Ban Treaty Organisanization's infra red station in Bemuda. The explosion was coincident with a cosmic body several metres across and according to NASA such meteors, on average, happen at least once a year. It had the blast energy of between 3 and 5 kilotons of TNT.

Rings around Uranus

At https://phys.org/news/2019-06-astronomers-uranus.html ... astronomers see a warm glow emanating from the rings of Uranus - via the ALMA telescope array. Its most prominent ring is composed of golf ball size rocks and larger - and there are 13 rings in all.

At https://phys.org/news/2019-06-stars-photons-revolutionize-space-flight.html ... star photons may revolutionise space flight - the solar sail. It has no engine, uses no fuel, and has no solar panels. Instead, it harnesses the momentum of light energy (photons). Will it work?

The Maunder Minimum

At https://malagabay.wordpress.com/2019/06/17/maunder-minimum-and-the-comet... ... the Maunder Minimum (a very cold episode supposedly associated with a lack of sun spots) is under scrutiny by Tim Cullen. A volcanic event is visible in Alpine ice cores. However, cometary dust may have prolonged the Minimum - the takeway part of the post. The Great Comet of 1744, naked eye visible for several months, displayed an unusual feature - a fan of six tails. This has vexed astronomers as to why it might have happened.

Volcanic Dome on Ceres

At https://phys.org/news/2019-06-gravitational-dawn-dome-ceres-volcanic.html ... gravitational data beamed back by the Dawn mission suggests the dome on Ceres is a mud volcano - a mix of salty brine and solids. Volcanism is perhaps the key to understanding this but it was thought, until now, that volcanism was absent on such a small planet as Ceres (or is it a large asteroid). Not only that but they think the dome may be of recent date. It is in fact a mountain, or volcano, 4km in height and 17 km across.

Rhythm of the Planets

This story is at https://tallbloke.wordpress.com/2019/05/29/the-sun-follows-the-rhythm-of... ... Tall Bloke was especially interested in this new research as he, and colleagues, have been saying something similar for a long time and have generally been ignored. The German study corroborates the influence of planetary tidal forces on solar activity. They claim the tidal influences of Jupiter, Venus and the Earth affect the solar magnetic field thus governing the solar eleven year cycle.