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A team of researchers propose using the James Webb Space Telescope to look at five planets in the Venus Zone, a search that could reveal valuable insights into Earth’s future.
Venus floats in a nest of sulfuric acid clouds, has no water, and its surface temperatures are hot enough to melt lead. Despite being such a scorching wasteland, however, the planet is often referred to as Earth’s sister because of similarities in size, mass, density, and volume.
Earth and Venus, which both formed about 4.5 billion years ago, now sit on opposite ends of habitability. This leaves astronomers with a giant question: Is Venus Earth’s past or Earth’s future?
“It’s all about trying to understand why Earth and Venus are so different now,” says Jim Head, a professor of geological sciences at Brown University. “We have Venus to look at here, but there are solar systems out there in which we can actually compare all these different things that we want to know. It’s a whole new parameter of space to explore.”
In the study in the Astronomical Journal, Held and colleagues identify five Venus-like planets from a list of more than 300. The researchers selected these terrestrial planets orbiting other stars, called exoplanets, because they were the most likely to resemble Venus in terms of their radii, masses, densities, the shapes of their orbits, and distances from their stars.
The researchers rank the Venus-like planets depending on the brightness of the stars they orbit to increase the odds that the Webb Telescope gets the clearest view of them, enabling researchers to pull key signals from them regarding the composition of their atmospheres.
The five planets all orbit regions called the Venus Zone, which was coined by astrophysicist and study coauthor Stephen Kane from the University of California, Riverside.
The Venus Zone encompasses the region around a star where it’s too hot for a planet to have water but not too hot for it to have no atmosphere. It is similar to the concept of a habitable zone, which is a region around a star where liquid surface water could exist.
The researchers propose the planets identified in the paper as targets for the Webb telescope in 2024. Webb is NASA’s most ambitious telescope to date and is enabling scientists not only to look into the deep past of the universe but to peer into the atmospheres of exoplanets for telltale signs of what the planet is like.
Studying exoplanets in the Venus Zone could give astronomers a better understanding of whether Venus was ever habitable. The Webb observations the researchers propose, for example, may reveal biosignature gases in the atmosphere such as methane, methyl bromide, or nitrous oxide, which could signal the presence of life. The researchers also hope to see through the observations whether Venus’s lack of plate tectonics is common and whether the planet’s volcanic activity is normal.
These observations will be complemented by NASA’s two upcoming spacecraft missions to Venus. The DAVINCI mission will measure gases in the Venusian atmosphere. The VERITAS mission will enable 3D reconstructions of the landscape.
Combined, the findings will help lead to a better understanding of the Earth-Venus divergence, which could serve as a dire warning for where Earth is heading, the researchers say.
Colby Ostberg, a UC Riverside PhD student, is the study’s lead author. NASA’s Habitable Worlds Program supported the work.
Source: Brown University
The post Hunt for Venus-like planets could shed light on Earth’s future appeared first on Futurity.
A satellite built on a small budget and with off-the-shelf supplies could be a solution to space junk.
A team of students from Brown University sent the satellite—which is powered by 48 Energizer AA batteries and a $20 microprocessor popular with robot hobbyists—into space about 10 months ago, hitching a ride on Elon Musk’s SpaceX rocket.
Now, an analysis of data from Air Force Space Command shows that the satellite successfully operated. It could also have far-ranging impacts on efforts to cut down on the growing problem of space debris, which poses a potential danger to all current and future space vehicles.
According to NASA, there are now more than 27,000 pieces of what it calls orbital debris or space junk being tracked by the Department of Defense’s global Space Surveillance Network. Orbital debris ranges from any human-made object in Earth’s orbit that no longer serves a useful function, like nonfunctional spacecraft, abandoned launch-stage vehicles, mission-related debris, and fragmentation debris. It also includes defunct satellites that remain in orbit sometimes decades after their mission is complete.
That’s a problem, given that most satellites remain in orbit for an average of 25 years or more, says Rick Fleeter, an adjunct associate professor of engineering. So when his students got a once-in-a-lifetime chance to design and build their own satellite to be launched into space, they decided to engineer a potential solution.
The students added a 3D-printed drag sail made from Kapton polyimide film to the bread-loaf-sized cube satellite they built. Upon deployment at about 520 kilometers (323 miles)—well above the orbit of the International Space Station—the sail popped open like an umbrella and is helping to push the satellite back down to Earth sooner, according to initial data. In fact, the satellite is well below the other small devices that deployed with it. In early March, for instance, the satellite was at about 470 kilometers (292 miles) above the Earth while the other objects were still in orbit at about 500 kilometers or more.
“You can see in the tracking data that we’re visibly below everybody else and accelerating away from them,” Fleeter says. “You can see that our satellite is already descending toward reentry, whereas the others are still in a nice circular orbit higher up.”
The data suggest that the student satellite, called SBUDNIC, will be out of orbit within five years versus the estimated 25 to 27 years the students calculated for it without the drag device.
Fleeter and the students believe that their initial analysis of the publicly available tracking data serves as a proof of concept that this type of sail can be part of an effort to reduce the number of space debris in orbit around Earth. They hope similar sails can be added to other same-sized devices or scaled up to larger projects in the future.
“The theory and physics of how this works has been pretty well accepted,” Fleeter says. “What this mission showed was more about how you realize it—how you build a mechanism that does that, and how you do it so it’s lightweight, small, and affordable.”
The project is a result of a collaboration between researchers at Brown’s School of Engineering and the National Research Council of Italy. It is also supported by D-Orbit, AMSAT-Italy, La Sapienza-University of Rome, and the NASA Rhode Island Space Grant. The name of the satellite is a play on Sputnik, the first satellite to orbit the Earth, and is also an acronym for the project participants.
This is the second small satellite designed and built by Brown students that’s been sent into orbit in recent years. The previous satellite, EQUiSat, did 14,000 loops around the Earth before ending its mission and burning up upon re-entering the atmosphere at the end of 2020.
SBUDNIC, however, is believed to be the first of its kind that was sent into orbit made almost exclusively from materials not designed for use in space and at such an astronomically low-cost when compared to other objects in orbit. The total cost of the student-designed cube satellite was about $10,000.
“The large complex space missions we hear about in the news are amazing and inspiring, but they also send a message that space is only for those types of specialized initiatives,” Fleeter says. “Here, we’re opening up that possibility to more people… We’re not breaking down all the barriers, but you have to start somewhere.”
A group of about 40 students designed and built the satellite in one year. It started in the course Design of Space Systems, which Fleeter taught in Spring 2021. Italian aerospace company D-Orbit approached with an opening for a satellite on the SpaceX Falcon 9 rocket that would launch in one year. Fleeter turned to his students, who had just listened to their first seminars on space systems design, and presented them the opportunity. From there, the race was on.
The students began by conceptualizing and designing the individual subsystems of the satellite, often working with industry advisors who provided feedback and engineering guidance on the feasibility of their proposals. Students then put their plans into action, managing the technical aspects of the satellite along with coordinating the administrative pieces. The continual prototyping, testing, and improving required amounted to a herculean effort from students in terms of hours and brain power.
Students purchased materials they needed at local stores and online retail websites. They often had to engineer nifty workarounds to their materials so they could survive in space. The approach often meant coming up with test apparatuses that replicated specific environmental conditions of space, like the high vibration from the rocket launch, says Marco Cross, who graduated last year with a master’s degree in biomedical engineering and served as chief engineer for SBUDNIC.
For instance, the team used reptile heating lamps in a vacuum chamber to test the thermal shield they created to protect the satellite’s electronics from the sun.
To be cleared for launch, the satellite had to pass qualification tests and meet strict rules and regulations that SpaceX and NASA follow. “It is a zero-failure-tolerated environment,” Cross says. “The team never wavered.”
The students got the green light after a series of vacuum, thermal, and vibration tests. A group then traveled to Cape Canaveral in Florida to deliver SBUDNIC so it could be inserted into D-Orbit’s larger carrier satellite, which was then put onto the SpaceX rocket.
Along with presenting their findings at conferences and submitting their data to a publication, the SBUDNIC team is currently planning a series of presentations in schools throughout Rhode Island. They hope to inspire future innovators and make high school students more aware of the opportunities that exist for them in space engineering and design.
Source: Brown University
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