Friday (Feb. 28) is shaping up to be a delightful day for space explorers, as not one but two major NASA missions are expected to take to the skies — and interestingly, though the spacecraft associated with these missions are pretty different from one another, you might say they all have the same profession: cosmic cartography.
Cartographer one, named PUNCH, will map the sun’s dynamics, while cartographer two, named SPHEREx, will kind of map the rest of the universe.
“How does the universe work? How did we get here within that universe? And are we alone in that universe?” Shawn Domagal-Goldman, acting director of the Astrophysics Division at NASA Headquarters, pondered while speaking with reporters on Tuesday (Feb. 25). “Those are big enough where we can’t answer them with one instrument. We can’t even answer them with one mission. We need a full fleet to do that, and every time we fly a new telescope, we make sure that it adds to that fleet in ways that are unique from everything we’ve built before.”
At present, launch is scheduled to take place from Launch Complex 4E at Vandenberg Space Force Base in California no earlier than Friday at 10:09 p.m. EST (7:09 p.m. local time, and 0309 GMT on March 1). PUNCH’s four-satellite system and SPHEREx’s single conical structure will be riding atop a SpaceX Falcon 9 rocket as part of NASA’s Launch Services Program, which connects space missions with appropriate commercial launch vehicles.
“Heliophysics is catching a ride,” Joe Westlake, director of the Heliophysics Division at NASA Headquarters, said during the Tuesday press conference. “[It’s] going along with the SPHEREx launch, and really providing over and over again that value to the American taxpayer, having these two missions go up together.”
A new solar adventurer enters the villa
The PUNCH mission, which stands for Polarimeter to Unify the Corona and Heliosphere, is made of four small satellites — three wide-field imagers and a narrow-field imager — that’ll be stationed around Earth. Together, they’re built to create 3D views of the sun‘s outer atmosphere, or corona, as it turns into the solar wind that fills up our cosmic neighborhood’s enormous bubble, known as the heliosphere. Moreover, it’ll be doing so by tapping into polarized light patterns, which basically means it can reveal the directions of different features within the heliosphere.
“I think PUNCH is going to revolutionize our physical understanding of space weather events and how they propagate through the inner heliosphere on their way to the Earth,” Nicholeen Viall, PUNCH mission scientist at NASA’s Goddard Space Flight Center in Maryland, told reporters during the press conference.
For example, sometimes solar eruptions — blips of plasma that erupt from our star’s surface — can break off and shoot into space. This is called a coronal mass ejection, or CME. And due to its polarized light capabilities, the PUNCH mission will be able to understand the direction such a CME is moving in.
As Viall explained, its satellite vigilantes stationed around our planet should be able to paint a picture of whether a CME is coming toward Earth or if it’s headed elsewhere within our solar system. It won’t be the first spacecraft to deal with polarized light — the PUNCH team has emphasized that the STEREO spacecraft certainly have done so — but it could have the best polarized-light-related resolution.
“STEREO has looked in polarized light and has looked at the whole inner solar system, but not with this kind of resolution — not even close,” Viall said. “We’re doing 100 times better than what STEREO did, and we’re going and looking over the poles, and that requires a tremendous amount of sensitivity.”
The James Webb Space Telescope’s little brother
Then, on the other hand, you have the SPHEREx mission, which stands for Spectro-Photometer for the History of the Universe, Epoch of Reionization and Ices Explorer. Scientists like to compare SPHEREx to something you’re more than likely familiar with: the James Webb Space Telescope. Here’s why.
Like the JWST, SPHEREx will be peering out into the infrared universe.
This means it’ll be working with infrared light wavelengths coming from arcane sections of the cosmos in order to illuminate what happened during the chaotic first several moments of time. However, unlike the JWST, which creates highly in-depth portraits of relatively small sections of the sky, SPHEREx is going bigger. It’ll manage to capture sweeping, wide-angle images of the entire night sky.
“Imagine you’re a photographer that wants to capture wildlife in a forest,” Domagal-Goldman said. “You may take a camera designed to zoom in on a tree, or maybe even a nest and the eggs inside a nest on a tree — that’s what James Webb does. What SPHEREx does is, it’s the panoramic lens. It’s going to give us not that egg in a nest in a tree. It’s going to give us the forest and all the trees within it.”
“We’re going to produce 102 maps in 102 wavelengths every six months,” Phil Korngut, SPHEREx instrument scientist at the California Institute of Technology in Pasadena, told reporters during the Tuesday press conference.
With such a goal, Domagal-Goldman says SPHEREx should be able to help answer three key questions in astronomy. The first has to do with cosmic inflation, or the extreme way our universe seemed to “inflate” just after the Big Bang provoked the beginning of time. In short, how – and why — did the universe expand a trillion trillion fold, going from the size of an atom to the expanse we see today, in fractions of a second?
“If we can produce a map of what the universe looks like today and understand that structure, we can tie it back to those original moments just after the Big Bang,” Korngut said. “So the largest scales imaginable on billions of light-years across are tied to the smallest scales imaginable, just a tiny fraction of an atom.”
The second question, meanwhile, has to do with the evolution of galaxies, and the final one surrounds the origins of water and ice in our universe.
“Where is all the water? On Earth, we know that every living creature needs water to survive, but how and when did that water get here? And how might that work for planets around other stars?” Rachel Akeson, SPHEREx science data center lead at Caltech/IPAC, said during the press conference.
As I’m sure this article makes clear, both PUNCH and SPHEREx’s mere existence has already started to spur endless questions among scientists — and if these space explorers manage to fulfill their destinies and lead humanity to some long-awaited answers, I hope their creators will remember the delightful day that was Feb. 28, 2025.