Archive for the ‘Astronomy’ Category

Did ‘Oumuamua Come From a Dead Star?


(Syfy Wire::Bad Astronomy) – Phil Plait:

Late last year, an asteroid was discovered on a very unusual orbit: It was moving far too rapidly to be a member of our own solar system. Once enough observations were in, it became very clear that this was an object that came from another star, deep in interstellar space. It was a truly alien visitor.

A new paper makes an intriguing suggestion: It may have come from a white dwarf. …

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‘Oumuamua asteroid


A Unique Solstice


(Starts With A Bang!) – Ethan Siegel:

The December solstice – one of the two days where the Earth’s tilt is maximally inclined with respect to the Sun - brings a number of special things along with it that are unique to this time of year. …

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The Sun’s apparent path through the sky on the solstice

Solar System Exploration in 2018


(Planetary Blogs) – Emily Lakdawalla:

2018 is shaping up to be a very busy year in space exploration, with most of the action happening relatively close to Earth. There will be three launches to the Moon and one each toward Mars and Mercury. Two spacecraft will rendezvous with near-Earth asteroids and prepare to descend for samples. We’ll see the most distant ever planetary encounter with a tiny Kuiper belt object. And fifteen other spacecraft remain active in science missions at Venus, the Moon, Mars, Ceres, and Jupiter. …

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Solar system missions in 2018

Why NASA’s Kepler Mission Is Toast


(Starts With A Bang!) – Ethan Siegel:

All of Kepler’s major discoveries are in the past.

There are great advances to come, but Kepler has already seen almost all of what it’s going to, and practically all of the great science we’d hoped for has already been extracted. It’s time for the next step. It’s no longer satisfying to speculate about what could be out there. It’s time to know. …

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Kepler-90 planets

‘Oumuamua Not a Spacecraft


(Guardian Space) – Ian Sample:

The first scans for alien technology aboard a mysterious object that is barreling through the solar system have found no evidence it is the work of an intelligent civilisation. …

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Artist's impression of ‘Oumuamua asteroid

Alien Spacecraft Oumuamua?


(Independent) – Andrew Griffin:

The Breakthrough Listen team is using the Green Bank radio telescope in West Virginia, US, to study Oumuamua, which is named after the Hawaian term for “scout” or “messenger”. …

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The Largest Black Hole Merger Of All-Time Is Coming


(Starts With A Bang!) – Ethan Siegel:

Over in Andromeda, the nearest large galaxy to the Milky Way, a number of unusual systems have been found.

One of them, J0045+41, was originally thought to be two stars orbiting one another with a period of just 80 days. When additional observations were taken in the X-ray, they revealed a surprise: J0045+41 weren’t stars at all. Instead, Trevor Dorn-Wallenstein’s team discovered a distant supermassive black hole pair, purely by coincidence.

Powerful relativistic effects will cause this orbit to decay, leading to a merger within 1,000 years. …

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Polynesian Celestial Navigation in Moana


(Planetary Blogs) – Duane W. Hamacher & Carla Bento Guedes:

One of the greatest feats of human migration in history was the colonisation of the vast Pacific Ocean by Polynesian peoples. They achieved it thanks to their sophisticated knowledge of positional astronomy and celestial navigation.

The Disney film Moana has drawn attention to these accomplishments and helped inform a new generation about the complexity of Indigenous astronomy. …

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Moana, 2016 film

Standard Sirens


(Preposterous Universe) – Sean Carroll:

We’re already pretty good at measuring the expansion of the universe, using something called the cosmic distance ladder. You build up distance measures step by step, determining the distance to nearby stars, then to more distant clusters, and so forth. Works well, but of course is subject to accumulated errors along the way. This new kind of gravitational-wave observation is something else entirely, allowing us to completely jump over the distance ladder and obtain an independent measurement of the distance to cosmological objects. See this LIGO explainer. …

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Merging Neutron Stars

Is There Anybody Out There?


(Planetary Blogs) – Jason Davis:

The past, present and future of SETI, the search for extraterrestrial intelligence …

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Parkes radio telescope