From his lab in Missoula, Nate McCrady watches the stars.
The University of Montana associate professor of astronomy and his team of research students received a $1.125 million grant from NASA last year.
The grant funded a telescope purchase and three years of research work, allowing them to participate in Project MINERVA, a collaborative effort between four universities that will be examining the planets surrounding nearby stars to look for ones that are similar to Earth.
Each of the four universities taking part in Project MINERVA – UM, University of New South Wales in Australia, Harvard and Penn State – have all purchased identical telescopes that will all be placed at the Fred Lawrence Whipple Observatory on Mount Hopkins in Arizona.
One of the advantages of that location is that it averages around 300 clear nights every year.
Last week, McCrady, along with one of his research students, visited the observatory site to oversee final installation of the telescope and begin the tuning and calibration of the device and its software.
The telescopes used by University of New South Wales and UM are already in position. Harvard’s and Penn State’s are currently at the California Institute of Technology for calibration and testing.
Now that the telescope is up and running, it will be able to be remotely controlled as well as able to capture and transmit data to and from a research lab at UM, and the software that tells the telescopes what part of the sky to target each night was written by a UM student.
Once all of them are in place in February, McCrady said they will operate together by “flying in formation” allowing the researchers to have a similar level of power as that of a much larger telescope.
The four telescopes, each of which costs around $250,000, all have a 0.7-meter mirror, but when they are used in conjunction they have a similar effect to that of one 1.4-meter mirror.
“So instead of a single telescope that would cost four or five million dollars, we can get a similar result for about a million,” McCrady said.
He used the analogy of a telescope as a “light bucket.”
“If you are putting a bucket outside to collect rain, a bigger bucket catches more rain, or you can use more buckets,” he said. “We can collect more rain, or in our case starlight, with more smaller ones.”
Because they are taking photos of stars, McCrady said they don’t need the higher resolution that a larger mirror would provide.
Project MINERVA will have two phases once the array begins collecting images early next year. The first light phase will primarily be looking at nearby stars where there are already known planets to help characterize what type of planets they are. The telescopes will look to see how much and how long the starlight dims when a planet passes between them at the star.
“We know the mass of the planets, but don’t know the radius. Once you have both it will tell you about which are solid planets versus gas planets,” McCrady said.
The primary science of the telescope array will start in March when a piece of equipment called a spectrometer arrives. In this phase, the telescopes will survey around 100 nearby stars looking for additional planets that haven’t been seen before.
In this respect, McCrady said, the MINERVA array will be acting as a scouting mission for the next generation of large telescopes that will be coming online in the next decade, including the 2019 James Webb Space Telescope – which is the followup to the Hubble telescope – and the upcoming Thirty Meter Telescope in Hawaii.
“The time on them is very very valuable, so we’re going to look for the small planets around these stars to give them places to point to,” McCrady said.
He said UM’s involvement in MINERVA is a showpiece of the school’s scientific capabilities and is a sign of how much effort the school has been putting into improving the intensity of its research programs.
“It’s right on the front lines. It’s world-class science with top research quality equipment,” McCrady said.
The discovery of more Earth-like planets will allow researchers to better understand the factors that led to the formation of our planet
“Are planets like Earth common or is it rare to have an atmosphere like ours, photosynthesis, the ability for life?” McCrady said. “It captures the imagination, it’s so tangible, something you can picture standing on and exploring.”
In order to be sure about its findings, researchers typically need to observe a planet for two of its orbits. The initial NASA grant pays for three years of research.
“So that would be able to study a planet like Mars. If we wanted something like Jupiter, we would need 24 years,” McCrady said.