E S O E

LIGO Detects Gravitational Waves for Third Time

The newfound black hole has a final mass about 49 times that of our sun. This fills in a gap between the masses of the two merged black holes detected previously by LIGO, with solar masses of 62 (first detection) and 21 (second detection).

From the Now@Caltech press release

See also:

Physics Synopsis: LIGO Picks Up on the Third Ring

Physical Review Letters: GW170104: Observation of a 50-Solar-Mass Binary Black Hole Coalescence at Redshift 0.2 (PDF)

High-Resolution Visuals

EVERY KNOWN METEORITE FALL ON EARTH

This map shows every meteorite fall on Earth that we know about; where scientists have found either meteorites or impact craters. Some of these craters and meteorite fragments date as far back as the year 2300 BCE. The data for the image is from The Meteoritical Society and does not show places where meteorites might have fallen but no trace has yet been found.

To view the interactive map, where you can click on each meteorite spot to learn more and can also see more of the globe (eg Alaska and Antarctica), go here: http://bit.ly/Xmuvy5

The data used for the image is available here: http://bit.ly/VZzCrh

An alternative visualisation: http://bit.ly/12Yd1gA

-TEL

Braided Streams

Here’s one of my favorite fluvial features: braided streams.

The intricate network of joining, separating, and rejoining channels is what makes a stream braided. The braided channels shown here are part of the Brahmaputra River, which runs through Tibet.

Most braided streams form when a stream is “incompetent” or carries too much sediment. The excess sediment is deposited in sand bars that separate the channels, thus creating the intertwined look. Braided streams are especially common in glacial areas (where they often carry glacial melt laden with sediment) and in areas with variable seasonal flow. This particular river carries a lot of glacial flour, or very fine sediment that was powdered by glaciers—nature’s icy version of a mortar and pestle.

-CM