Gravitational waves and climate change

Since early 2018, I’ve contributed multiple articles to Mercury, the membership magazine for the Astronomical Society of the Pacific (ASP). These articles are only available in full to members of ASP, but recently Mercury has put extensive previews for certain articles up on the website as enticement to join. One of those articles is my piece about the GRACE Follow-On mission, which is simultaneously a project that measures the effects of climate change and is a testbed for the upcoming LISA gravitational-wave observatory.

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The Gravity of Climate Change

For Mercury:

Orbiting spacecraft are an essential tool for mapping worlds in the Solar System, providing information about everything from landforms to magnetic fields. Repeated monitoring helps scientists measure variations in a planet as the seasons change. That’s particularly true for the planet we know best, and one that is experiencing the biggest variations of all the worlds in the Solar System: Earth.

The Gravity Recovery and Climate Experiment Follow-On (GRACE-FO) mission consists of twin space probes designed to measure Earth’s gravity to high resolution. That measurement is important for geology—seismic activity and other substantial shifts in Earth’s crust—but also for tracking shifts in water and ice around the world. Those variations help researchers measure the melting of polar ice, along with more subtle phenomena like the depletion of aquifers in western North America and India, for example.

In addition to its essential work measuring ice melting and climate change, GRACE-FO will test a vital component of the Laser Interferometer Space Antenna (LISA), the planned space-based gravitational wave observatory that will continue the work of LIGO and its Earth-based observatories.

[Read the rest of the preview in Mercury]

Listening to the sounds of the cosmos

[ This blog is dedicated to tracking my most recent publications. Subscribe to the feed to keep up with all the science stories I write! ]

Last year, I went to a conference in Florida to hear — and in some cases meet — some of the leading thinkers in the study of gravitational waves. These waves are disturbances in the structure of spacetime itself, and could provide information about some exciting phenomena, if we can learn to detect them. The universe as heard in gravitational waves includes colliding black holes, white dwarfs locked in mutual orbits, exploding stars, and possibly chaotic disturbances from the very first instants after the Big Bang. This story marks one of my first big magazine articles, which I wrote for Smithsonian Air & Space magazine.

The Universe is Ringing

And astronomers are building observatories to listen to it

For Smithsonian Air & Space:

Think of it as a low hum, a rumble too deep to notice without special equipment. It permeates everything—from the emptiest spot in space to the densest cores of planets. Unlike sound, which requires air or some other material to carry it, this hum travels on the structure of space-time itself. It is the tremble caused by gravitational radiation, left over from the first moments after the Big Bang.

Gravitational waves were predicted in Albert Einstein’s 1916 theory of general relativity. Einstein postulated that the gravity of massive objects would bend or warp space-time and that their movements would send ripples through it, just as a ship moving through water creates a wake. Later observations supported his conception. [Read the rest at Air & Space….]