Category Archives: astronomy

Come Sail Away

Exploration and Travel are the Keys to the Cosmos

sunset over bermuda and travel
Come sail away and travel the planet… or out to the stars!

I’m listening to Styx’s Come Sail Away piece right now and it really brightened a cold, winter morning.  Not that I’m sad; quite the opposite. I just returned from two periods of extended travel to Iceland and Europe. My task: to serve as an astronomy lecturer for Smithsonian Journeys on a land trip. That was followed aa few weeks later by an assignment on a transatlantic cruise.  They were fabulous experiences. On the cruise, I had the privilege of bringing my mom along as my guest.  We had fun times, fun experiences, and  it was another chance to share the cosmos with fellow travelers.

Each time I go on a journey, I think about how much travel can broaden a person’s horizons. It doesn’t have to be very far  — many people find inspiration as they travel from one town to another, or even to another neighborhood in their own metropolis. The important thing is that when a person travels to a new environment, be it next door or around the world, they see a new vista, a distant horizon, and meet new and different people.

Travel and Exploration are How We Learn

That’s the essence of exploration – to learn new things from new places. It’s why I enjoy going around sharing astronomy and space science with others. It’s sort of a “meta” experience — reaching out to others about how we explore the universe and what we learn about it (and ourselves). That’s probably why I am so fascinated with astronomy and space exploration; they are important journeys to make, and the journey of my life has been to study astronomy and then share it with others. Each time we look up and out, we make progress toward understanding our place in the universe. each time we travel around our own planet, we make progress in understanding our brothers and sisters on this planet, and the places they live in. Progress is the greatest journey of all.

 

The Radio Sky Through Human Eyes

Check out the MWA Sky

The sky as seen by MWA
Title screen from a video about MWA.

Interested in the radio sky at low frequencies?  Then,check out the Murchison Wide-field Array (MWA). A few years ago, we worked on a video about the MWA, located in the outback of Western Australia. The video was created for the MIT Haystack Observatory, which was involved with the project. We interviewed Colin Lonsdale, who is director of Haystack, and created a short explainer about the observatory.  It was a fun project and I’ve kept tabs on the MWA’s progress ever since.

A Sky in Radio Technicolor

radio sky
The MWA sky, as seen by the GLEAM survey.

Recently the folks who run MWA released an image from a sky survey they’ve made called GLEAM (which stands for GaLactic and Extragalactic All-sky MWA). The combined MWA receivers scanned the sky at frequencies between 70 and 230 MHz. These are very low-frequency waves that can be easily disrupted by TV and radio signals (among others). So, MWA is located literally in the middle of nowhere with a fine view of the sky.  In the image they released, red denotes the lowest frequencies received, green is the middle of the range, and blue indicates the highest ones. This is what gives the image its ‘technicolor’ look. That works for our eyes, which can only see three primary colors.  MWA actually detects more than 20 colors.

What Does MWA “See”?

Among the objects that MWA can detect in its frequency bands are ancient supernova explosions and emissions from distant black holes. They are just a few of the types of celestial sites that lie in the 24,402 square degrees of sky that the MWA covered in the survey. In that region, there are more than 307,000 radio sources.   If you’re interested in the full paper from the survey team, it’s available here and gives all the details about the survey and data reduction.

MWA’s survey is part of the path to the final deployment of the low-frequency part of the Square Kilometre Array. Once built out, SKA will build on MWA’s work, further defining and refining the radio sky at radio frequencies well below what other arrays are detecting. In particular, the work will help astronomers dig further into the distant, early universe.  That’s still a largely unstudied realm of the cosmos, and astronomers are anxious to learn more about what happened way back then.