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November 29, 2023November 29, 2023 by Matt Williams

Odyssey Gives Us a Cool New View of Mars

This unusual view of the horizon of Mars was captured by NASA’s Odyssey orbiter using its THEMIS camera, in an operation that took engineers three months to plan. It’s taken from about 250 miles above the Martian surface – about the same altitude at which the International Space Station orbits Earth. NASA/JPL-Caltech/ASU

Chances are that you’ve seen images of Earth from space, thanks to the astronauts aboard the International Space Station (ISS), who regularly share stunning photos of our planet. These images provide us regularly with breathtaking views of cities, oceans, storms, eruptions, clouds, the curvature of the planet, and the way the atmosphere glows against the horizon. Thanks to NASA’s Mars Odyssey Orbiter, which has been in orbit for over 22 years, we now have an equally breathtaking view of Mars from orbit that captured what its curvature and atmosphere look like from space.

November 29, 2023November 29, 2023 by David Dickinson

The Solar Radius Might Be Slightly Smaller Than We Thought

SDO Sol — NASA SDO's view, of our tempestuous host star. NASA/SDO

Two astronomers use a pioneering method to suggest that the size of our Sun and the solar radius may be due revision.

Our host star is full of surprises. Studying our Sun is the most essential facet of modern astronomy: not only does Sol provide us with the only example of a star we can study up close, but the energy it provides fuels life on Earth, and the space weather it produces impacts our modern technological civilization.

Now, a new study, titled The Acoustic Size of the Sun suggests that a key parameter in modern astronomy and heliophysics—the diameter of the Sun—may need a slight tweak.

November 28, 2023November 28, 2023 by Matt Williams

Why Don't We See Robotic Civilizations Rapidly Expanding Across the Universe?

The central region of the Milky Way, also known as the Zone of Avoidance. Credit: ESO/S. Brunier

In 1950, while sitting down to lunch with colleagues at the Los Alamos Laboratory, famed physicist and nuclear scientist Enrico Fermi asked his famous question: “Where is Everybody?” In short, Fermi was addressing the all-important question that has plagued human minds since they first realized planet Earth was merely a speck in an infinite Universe. Given the size and age of the Universe and the way the ingredients for life are seemingly everywhere in abundance, why haven’t we found any evidence of intelligent life beyond Earth?

This question has spawned countless proposed resolutions since Fermi’s time, including the infamous Hart-Tipler Conjecture (i.e., they don’t exist). Other interpretations emphasize how space travel is hard and extremely time and energy-consuming, which is why species are likely to settle in clusters (rather than a galactic empire) and how we are more likely to find examples of their technology (probes and AI) rather than a species itself. In a recent study, mathematician Daniel Vallstrom examined how artificial intelligence might be similarly motivated to avoid spreading across the galaxy, thus explaining why we haven’t seen them either!

November 26, 2023November 26, 2023 by Matt Williams

Next Generation Space Telescopes Could Use Deformable Mirrors to Image Earth-Sized Worlds

The Roman Space Telescope Coronagraph during assembly of the static optics at NASA’s Jet Propulsion Laboratory Credits: Dr. Eduardo Bendek

Observing distant objects is no easy task, thanks to our planet’s thick and fluffy atmosphere. As light passes through the upper reaches of our atmosphere, it is refracted and distorted, making it much harder to discern objects at cosmological distances (billions of light years away) and small objects in adjacent star systems like exoplanets. For astronomers, there are only two ways to overcome this problem: send telescopes to space or equip telescopes with mirrors that can adjust to compensate for atmospheric distortion.

Since 1970, NASA and the ESA have launched more than 90 space telescopes into orbit, and 29 of these are still active, so it’s safe to say we’ve got that covered! But in the coming years, a growing number of ground-based telescopes will incorporate adaptive optics (AOs) that will allow them to perform cutting-edge astronomy. This includes the study of exoplanets, which next-generation telescopes will be able to observe directly using coronographs and self-adjusting mirrors. This will allow astronomers to obtain spectra directly from their atmospheres and characterize them to see if they are habitable.

November 25, 2023November 25, 2023 by Matt Williams

Ariane 6 Fires its Engines, Simulating a Flight to Space

The Ariane 6 rocket test firing on its launch pad at the European Spaceport in French Guiana. Credit: ESA

Since 2010, the European aerospace manufacturer ArianeGroup has been developing the Ariane 6 launch vehicle, a next-generation rocket for the European Space Agency (ESA). This vehicle will replace the older Ariane 5 model, offering reduced launch costs while increasing the number of launches per year. In recent years, the ArianeGrouip has been putting the rocket through its paces to prepare it for its first launch, which is currently scheduled for 2024. This past week, on Wednesday, November 23rd, the Ariane 6 underwent its biggest test to date as ground controllers conducted a full-scale dress rehearsal.

November 23, 2023November 23, 2023 by Matt Williams

NASA is Getting the Plutonium it Needs for Future Missions

Close-up of NASA’s Perseverance Mars rover as it looks back at its wheel tracks on March 17, 2022, the 381st Martian day, or sol, of the mission. Credit: NASA

Radioisotope Thermoelectric Generators (RTGs) have a long history of service in space exploration. Since the first was tested in space in 1961, RTGs have gone on to be used by 31 NASA missions, including the Apollo Lunar Surface Experiments Packages (ALSEPs) delivered by the Apollo astronauts to the lunar surface. RTGs have also powered the Viking 1 and 2 missions to Mars, the Ulysses mission to the Sun, Galileo mission to Jupiter, and the Pioneer, Voyager, and New Horizons missions to the outer Solar System – which are currently in (or well on their way to) interstellar space.

In recent years, RTGs have allowed the Curiosity and Perseverance rovers to continue the search for evidence of past (and maybe present) life on Mars. In the coming years, these nuclear batteries will power more astrobiology missions, like the Dragonfly mission that will explore Saturn’s largest moon, Titan. In recent years, there has been concern that NASA was running low on Plutonium-238, the key component for RTGs. Luckily, the U.S. Department of Energy (DOE) recently delivered a large shipment of plutonium oxide, putting it on track to realize its goal of regular production of the radioisotopic material.

November 21, 2023November 21, 2023 by Matt Williams

SpaceX Tested Its Starship Again. Successful Launch But Both Vehicles Were Destroyed

The SN25 Starship and BN9 booster on the landing pad at Boca Chica, Texas. Credit: SpaceX

After months of waiting, SpaceX made its second attempt at an orbital flight this past Saturday (November 18th). During their previous attempt, which occurred back in April, a fully-stacked Starship (SN24) and Super Heavy (BN7) prototypes managed to make it off the landing pad and reach an altitude of about 40 km (25 miles) above sea level. Unfortunately, the SN24 failed to separate from the BN7 booster a few minutes into the flight, causing the vehicle to fall into an uncontrolled tumble and forcing the ground teams to detonate the onboard charges.

Things went better this time as the SN25 and BN9 prototypes took off at about 7:00 AM local time (8:00 AM EDT; 05:00 AM PDT) from the Starbase launch complex. The SN25 successfully separated from its booster two minutes and fifty seconds later – at an altitude of 70 km (43 mi) – and reached an altitude of about 148 kilometers (92 miles), just shy of SpaceX’s goal of 150 km (~93 mi). However, the booster stage was lost about 30 seconds after separation, exploding over the Gulf of Mexico. The SN25 also exploded about eight minutes into the flight, reportedly because its flight termination system was activated.

November 21, 2023November 21, 2023 by David Dickinson

ESA’s Juice Mission is Approaching Earth. Why Has it Come Home Before Visiting Jupiter?

JUICE Prepares for a first of its kind double-flyby next year.

A Jupiter-bound mission adjusted its course last week…for a rendezvous with Earth. The European Space Agency’s (ESA) Jupiter Icy moons Explorer (JUICE) fired its thrusters for 43 minutes on Friday, November 17^th. This sets the mission up for a first of its kind double-flyby next year on August 23^rd, as it passes the Moon and then the Earth to pick up momentum.

November 19, 2023November 19, 2023 by Matt Williams

NASA Tests a Prototype Europa Lander

Testing Hardware for Potential Future Landing on Europa. Credit: NASA JPL-Caltech

In 2024, NASA will launch the Europa Clipper, the long-awaited orbiter mission that will fly to Jupiter (arriving in 2030) to explore its icy moon Europa. Through a series of flybys, the Clipper will survey Europa’s surface and plume activity in the hopes of spotting organic molecules and other potential indications of life (“biosignatures”). If all goes well, NASA plans to send a follow-up mission to land on the surface and examine Europa’s icy sheet and plumes more closely. This proposed mission is aptly named the Europa Lander.

While no date has been set, and the mission is still in the research phase, some significant steps have been taken to get the Europa Lander to the development phase. This past August, engineers at NASA’s Jet Propulsion Laboratory (JPL) in Southern California tested a prototype of this proposed landing system in a simulated environment. This system combines hardware used by previous NASA lander missions and some new elements that will enable a mission to Europa. It also could be adapted to facilitate missions to more “Ocean Worlds” and other celestial bodies in our Solar System.

November 18, 2023November 18, 2023 by Matt Williams

Under Some Conditions, Comets Could Deliver Organic Molecules to Planets

This artwork shows a rocky planet being bombarded by comets. Image credit: NASA/JPL-Caltech

Approximately 4.1 to 3.8 billion years ago, the planets of the inner Solar System experienced many impacts from comets and asteroids that originated in the outer Solar System. This is known as the Late Heavy Bombardment (LHB) period when (according to theory) the migration of the giant planets kicked asteroids and comets out of their regular orbits, sending them hurtling towards Mercury, Venus, Earth, and Mars. This bombardment is believed to have distributed water to the inner Solar System and maybe the building blocks of life itself.

According to new research from the University of Cambridge, comets must travel slowly – below 15 km/s (9.32 mi/s) – to deliver organic material onto other planets. Otherwise, the essential molecules would not survive the high speed and temperatures generated by atmospheric entry and impact. As the researchers found, such comets are only likely to occur in tightly bound systems where planets orbit closely to each other. Their results show that these systems would be a good place to look for evidence of life (biosignatures) beyond the Solar System.