Peering into the Cosmos

UM astrophysicist leads NASA mission to study X-ray emissions from the Milky Way and outer space

In the midst of an Alaskan winter, scientists from NASA and academic institutions around the world gathered together to launch four rockets into outer space with hopes to better understand the secrets of the cosmos.

Officially named the 2018 Poker Flat Sounding Rocket Campaign, the endeavor consists of two separate missions: One lead by the University of Miami explores X-ray emissions coming from outer space and our galaxy; the other studies how microscopic ice particles found 53 miles above the Earth, called Polar Mesospheric Clouds (PMCs), are formed. 

Massimiliano Galeazzi, associate chair and professor of physics at the University of Miami, is the principal investigator for the DXL (Diffuse X-rays from the Local Galaxy) mission. Galeazzi says the DXL mission is designed to study X-rays coming from two different sources in space.

“The first source,” he said, “is located outside our solar system and is generated by remnants of multiple supernovae explosions forming what is now called the Local Hot Bubble region of our galaxy. The second source is within the solar system and is generated by the solar wind interacting with neutral gas in the solar system and Earth’s atmosphere.”

The DXL mission seeks to gain a better understanding of the nature and characteristics of these sources, specifically the X-rays produced when the solar wind, which is composed when heavily charged ions are emitted by the sun and interact with the Earth’s neutral gasses—hydrogen and helium—found in our atmosphere. “This phenomenon is called solar wind charge exchange,” he adds, “and we are studying it, primarily, so we can remove its contribution from astrophysical observations, but also to better understand the physics of the phenomenon.”

According to Galeazzi, when observing an object outside the solar system the solar wind charge exchange interferes with how it is observed from Earth. To properly understand the properties of these objects, scientists must be able to understand the contribution from solar wind charge exchange and remove it from the observation or they could get erroneous results.

“For example, if you take a photograph of a distant object, but you have a light source close to you, the distant object may be hard to see because of that light source, so to be able to get a nice picture, you must first remove the contribution of that source,” said Galeazzi.

The DXL mission was successfully launched at 3:17 a.m. local time on January 19, 2018.  Along with Galeazzi’s DXL mission, three other rockets (all waiting for good conditions to be propelled into space) will determine how large quantities of water could affect the upper atmosphere and form Polar Mesospheric Clouds (PMCs). This mission, named Super Soaker, will measure the impact of short-term changes on PMCs, which are often used to quantify changes in Earth’s upper atmosphere over many decades.

The DXL mission launched from the Poker Flat Research range in Alaska, which is near the Earth’s magnetic poles and allows researchers to take X-ray measurements closer to the region where the solar magnetic field interacts with Earth’s magnetic field.

In addition to the University of Miami, the DXL collaboration includes scientists from different institutions, including NASA’s Goddard Space Flight Center, LATMOS in France, the University of Wisconsin, John Hopkins University, and Boston University. It is financially supported by the Astrophysics Division of NASA’s Science Mission Directorate and logistically by NASA’s sounding rocket division at Wallops Flight Facility. 

UM Professor Galeazzi inspects the rocket before launch in Alaska.
(photo credit: NASA)


Scientists prep for launch of the DXL mission. (photo credit: NASA)


The DXL mission rocket is propelling into space at 3:17 a.m.
(photo credit: Merrick Peirce, Fairbanks, AK)





January 25, 2018