NASA Archives

December 8, 2023December 9, 2023 by Matt Williams

If Our Part of the Universe is Less Dense, Would That Explain the Hubble Tension?

Ten areas in the sky were selected as “deep fields” that the Dark Energy Camera imaged several times during the survey, providing a glimpse of distant galaxies and helping determine their 3D distribution in the cosmos. Credit: NSF/DES/NOIRLab/DOE/FNAL/AURA/University of Alaska Anchorage/

In the 1920s, Edwin Hubble and Georges Lemaitre made a startling discovery that forever changed our perception of the Universe. Upon observing galaxies beyond the Milky Way and measuring their spectra, they determined that the Universe was expanding. By the 1990s, with the help of the Hubble Space Telescope, scientists took the deepest images of the Universe to date and made another startling discovery: the rate of expansion is speeding up! This parameter, denoted by Lambda, is integral to the accepted model of cosmology, known as the Lambda Cold Dark Matter (LCDM) model.

Since then, attempts to measure distances have produced a discrepancy known as the “Hubble Tension.” While it was hoped that the James Webb Space Telescope (JWST) would resolve this “crisis in cosmology,” its observations have only deepened the mystery. This has led to several proposed resolutions, including the idea that there was an “Early Dark Energy” shortly after the Big Bang. In a recent paper, an international team of astrophysicists proposed a new solution based on an alternate theory of gravity that states that our galaxy is in the center of an “under-density.”

December 8, 2023December 8, 2023 by Laurence Tognetti

The International Space Station Celebrates 25 Years in Space

NASA recently celebrated the 25^th anniversary of the International Space Station (ISS) with a space-to-Earth call between the 7-person Expedition 70 crew and outgoing NASA Associate Administrator, Bob Cabana, and ISS Program Manager, Joel Montalbano. On December 6, 1998, the U.S.-built Unity module and the Russian-built Zarya module were mated in the Space Shuttle Endeavour cargo bay, as Endeavour was responsible for launching Unity into orbit that same day, with Zarya having waited in orbit after being launched on November 20 from Kazakhstan.

December 7, 2023December 9, 2023 by Scott Alan Johnston

OSIRIS-REx Failed to Deploy its Drogue Chute Properly. Now NASA has Figured out Why

A training model of the OSIRIS-REx sample return capsule, August 30, 2023. Credit: NASA/Keegan Barber.

On September 24, 2023, NASA’s OSIRIS-REx mission returned a precious sample of rocky material from asteroid Bennu to Earth. The capsule landed safely under its main parachute, but it arrived more than a minute early. The cause: a small drogue parachute, designed to slow the spacecraft down prior to the main chute’s deployment, failed to open. After an investigation into the mishap, NASA believes they have determined the cause of the (happily non-catastrophic) failure.

December 4, 2023December 4, 2023 by Matt Williams

How Can Astronauts Maintain Their Bodies With Minimal Equipment?

NASA astronauts Bob Hines and Kjell Lindgren work out on the Advanced Resistive Exercise Device (ARED). Credits: NASA

Decades of research aboard the International Space Station (ISS) and other spacecraft in Low Earth Orbit (LEO) have shown that long-duration stays in microgravity will take a toll on human physiology. Among the most notable effects are muscle atrophy and bone density loss and effects on eyesight, blood flow, and cardiovascular health. However, as research like NASA’s Twin Study showed, the effects extend to organ function, psychological effects, and gene expression. Mitigating these effects is vital for future missions to the Moon, Mars, and other deep-space destinations.

To reduce the impact of microgravity, astronauts aboard the ISS rely on a strict regiment of resistance training, proper diet, and cardiovascular exercise to engage their muscles, bones, and other connective tissues that comprise their musculoskeletal systems. Unfortunately, the machines aboard the ISS are too large and heavy to bring aboard spacecraft for long-duration spaceflights, where space and mass requirements are limited. To address this, NASA is investigating whether exercise regimens that rely on minimal or no equipment could provide adequate physical activity.

December 4, 2023December 4, 2023 by Matt Williams

Europa Clipper Could Help Discover if Jupiter's Moon is Habitable

Artist's concept of a Europa Clipper mission. Credit: NASA/JPL

Since 1979, when the Voyager probes flew past Jupiter and its system of moons, scientists have speculated about the possibility of life within Europa. Based on planetary modeling, Europa is believed to be differentiated between a rocky and metallic core, an icy crust and mantle, and a liquid-water ocean that could be 100 to 200 km (62 to 124 mi) deep. Scientists theorize that this ocean is maintained by tidal flexing, where interaction with Jupiter’s powerful gravitational field leads to geological activity in Europa’s core and hydrothermal vents at the core-mantle boundary.

Investigating the potential habitability of Europa is the main purpose of NASA’s Europa Clipper mission, which will launch on October 10th, 2024, and arrive around Jupiter in April 2030. However, this presents a challenge for astrobiologists since the habitability of Europa is dependent on many interrelated parameters that require collaborative investigation. In a recent paper, a team of NASA-led researchers reviewed the objectives of the Europa Clipper mission and anticipated what it could reveal regarding the moon’s interior, composition, and geology.

November 30, 2023November 30, 2023 by Matt Williams

Fermi has Found More than 300 Gamma-Ray Pulsars

Visualization of a fast-rotating pulsar. Credit: NASA's Goddard Space Flight Center Conceptual Image Lab

In June 2008, the Gamma-ray Large Area Space Telescope began surveying the cosmos to study some of the most energetic phenomena in the Universe. Shortly after that, NASA renamed the observatory in the Fermi Gamma-ray Space Telescope in honor of Professor Enrico Fermi (1901-1954), a pioneer in high-energy physics. During its mission, Fermi has addressed questions regarding some of the most mysterious and energetic phenomena in the Universe – like gamma-ray bursts (GRBs), cosmic rays, and extremely dense stellar remnants like pulsars.

Since it began operations, Fermi has discovered more than 300 gamma-ray pulsars, which have provided new insights into the life cycle of stars, our galaxy, and the nature of the Universe. This week, a new catalog compiled by an international team contains the more than 300 pulsars discovered by the Fermi mission – which includes 294 confirmed gamma-ray-emitting pulsars and another 34 candidates awaiting confirmation. This is 27 times the number of pulsars known to astronomers before the Fermi mission launched in 2008.

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 28, 2023November 28, 2023 by Laurence Tognetti

Titan Dragonfly is Go!…. for Phase C

Artist’s rendition of NASA’s Dragonfly on the surface of Titan. (Credit: NASA/Johns Hopkins APL/Steve Gribben)

The surface exploration of Saturn’s largest moon, Titan, just got one step closer to reality as NASA’s much-anticipated Dragonfly mission recently received approval from the powers that be to advance to Phase C, which is designated as Final Design and Fabrication, according to NASA’s Systems Engineering Handbook. This comes after the Dragonfly team successfully completed all the requirements for Phase B in March 2023, also known as the Preliminary Design Review or Preliminary Design and Technology Completion in the NASA Systems Engineering Handbook.

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 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.