Whale geologists

The voice of the fin whale penetrates the earth’s crust beneath the sea floor – a whale born ultrasound.

 

The Earth’s layered structure. (1) inner core; (2) outer core; (3) lower mantle; (4) upper mantle; (5) lithosphere; (6) crust. Wikimedia commons.

Sailing stones – a SOLVED scientific mystery

Have you heard of the sailing stones?

One of the strangest natural phenomena ever identified, these are dolomite and syenite rocks around 8-17 kg that rest on the flat, barren lakebed known as the “racetrack” in Death Valley. And move. Yes, that’s right. They move. And they leave skidmarks behind them.

Different rocks even move in different ways. Lighter ones move more. Rough-bottomed rocks move in straight lines, whilst smooth ones wander.

The mystery has bewitched researchers and the public alike since the early 1900s. The movements are rare, and no one had been able to observe them and so identify the cause – until December 2013.

 

A sailing stone in Death Valley. By Lgcharlot - via Wikipedia Commons.

The methane mystery

The methane mystery Methane on Mars is really interesting – and really hard to explain.

On Earth, methane signals microbes: they produce it, lots, as they break down organic matter. Although there are other, non-living sources of methane, such as some geological processes, it is generally considered a useful biomarker: i.e. if you find methane, you may have found life. No wonder scientists are all excited to find lots of it.

At least, lots according to the Mars Curiosity Rover. But very little according to the ExoMars Trace Gas Orbiter (TGO) – which is where most of the mystery comes in.

 

Artist's impression of the Curiosity landing on Mars – NASA.