Matt Williams, Author at Universe Today

August 6, 2024August 6, 2024 by Matt Williams

Elliptical Orbits Could be Essential to the Habitability of Rocky Planets

Illustration of Kepler-186f, a recently-discovered, possibly Earthlike exoplanet that could be a host to life. (NASA Ames, SETI Institute, JPL-Caltech, T. Pyle) — This is Kepler 186f, an exoplanet in the habitable zone around a red dwarf. We've found many planets in their stars' habitable zones where they could potentially have surface water. But it's a fairly crude understanding of true habitability. Image Credit: NASA Ames, SETI Institute, JPL-Caltech, T. Pyle)

A seismic shift occurred in astronomy during the Scientific Revolution, beginning with 16th-century polymath Copernicus and his proposal that the Earth revolved around the Sun. By the 17th century, famed engineer and astronomer Galileo Galilei refined Copernicus’ heliocentric model using observations made with telescopes he built himself. However, it was not until Kepler’s observations that the planets followed elliptical orbits around the Sun (rather than circular orbits) that astronomical models matched observations of the heavens completely.

As it turns out, this very quirk of orbital mechanics may be essential to the emergence of life on planets like Earth. That was the hypothesis put forth in a recent study by a team of astronomers led by the University of Leeds. According to their work, orbital eccentricity (how much a planet’s orbit deviates from a circle) can influence a planet’s climate response, which could have a profound effect on its potential habitability. These findings could be significant for exoplanet researchers as they continue to search for Earth-like planets that could support life.

August 5, 2024August 5, 2024 by Matt Williams

Habitable Planet’s Orbiting Red Dwarf Suns Could at Risk from Far-Ultraviolet Radiation

Artist's depiction of red-dwarf-flare. Image credit: Casey Reed/NASA

The question of whether or not red dwarf stars can support habitable planets has been subject to debate for decades. With the explosion in exoplanet discoveries in the past two decades, the debate has become all the more significant. For starters, M-type (red dwarf) stars are the most common in the Universe, accounting for 75% of the stars in our galaxy. Additionally, exoplanet surveys indicate that red dwarfs are particularly good at forming Earth-like rocky planets that orbit within their circumsolar habitable zones (CHZs).

Unfortunately, a considerable body of research has shown that planets orbiting red dwarf suns would be subject to lots of flare activity – including some so powerful they’re known as “superflares.” In a recent study led by the University of Hawai’i, a team of astrophysicists revealed that red dwarf stars can produce stellar flares with significantly more far-ultraviolet radiation than previously expected. Their findings could have drastic implications for exoplanet studies and the search for extraterrestrial life on nearby rocky planets.

August 2, 2024August 2, 2024 by Matt Williams

China's Lunar Samples Contain Graphene Flakes

Artist’s impression of the graphenes (C24) and fullerenes found in a Planetary Nebula. The detection of graphenes and fullerenes around old stars as common as our Sun suggests that these molecules and other allotropic forms of carbon may be widespread in space. Credits: IAC; original image of the Helix Nebula (NASA, NOAO, ESA, the Hubble Helix Nebula Team, M. Meixner, STScI, & T.A. Rector, NRAO.)

In 2004, scientists at the University of Manchester first isolated and investigated graphene, the supermaterial composed of single-layer carbon atoms arranged in a hexagonal honeycomb lattice. Since then, it has become a wonder, with properties that make it extremely useful in numerous applications. Among scientists, it is generally believed that about 1.9% of carbon in the interstellar medium (ISM) exists in the form of graphene, with its shape and structure determined by the process of its formation.

As it happens, there could be lots of this supermaterial on the surface of the Moon. In a recent study, researchers from the Chinese Academy of Science (CAS) revealed naturally formed graphene arranged in a special thin-layered structure on the Moon. These findings could have drastic implications for our understanding of how the Moon formed and lead to new methods for the manufacture of graphene, with applications ranging from electronics, power storage, construction, and supermaterials. They could also prove useful for future missions that will create permanent infrastructure on the lunar surface.

July 31, 2024July 31, 2024 by Matt Williams

A New Study Shows How our Sun Could Permantly Capture Rogue Planets!

This illustration shows a rogue planet traveling through space. Credit: NASA/JPL-Caltech/R. Hurt (Caltech-IPAC)

Interest in interstellar objects (ISOs) was ignited in 2017 when ‘Oumuamua flew through our Solar System and made a flyby of Earth. Roughly two years later, another ISO passed through our Solar System – the interstellar comet 2I/Borisov. These encounters confirmed that ISOs are not only very common, but pass through our Solar System regularly – something that astronomers have suspected for a long time. Even more intriguing is that some of these objects are captured and can still be found orbiting our Sun.

In a recent study, a team of researchers described a region in the Solar System where objects can be permanently captured from interstellar space. Their analysis determined that once objects are captured by our Sun’s gravitational pull and fall into this region—which could include comets, asteroids, and even rogue planets—they will remain in orbit around the Sun and not collide with it. These findings could have drastic implications for ISO studies and proposed missions to rendezvous with some of these objects in the near future.

July 27, 2024July 27, 2024 by Matt Williams

Mercury Could be Housing a Megafortune Worth of Diamonds!

Image of Mercury taken by NASA's MESSENGER mission. Credit: NASA/JHUAPL/ASU/Carnegie Institution of Washington

Mercury, the closest planet to our Sun, is also one of the least understood in the Solar System. On the one hand, it is similar in composition to Earth and the other rocky planets, consisting of silicate minerals and metals differentiated between a silicate crust and mantle and an iron-nickel core. But unlike the other rocky planets, Mercury’s core makes up a much larger part of its mass fraction. Mercury also has a mysteriously persistent magnetic field that scientists still cannot explain. In this respect, Mercury is also one of the most interesting planets in the Solar System.

But according to new research, Mercury could be much more interesting than previously thought. Based on new simulations of Mercury’s early evolution, a team of Chinese and Belgian geoscientists found evidence that Mercury may have a layer of solid diamond beneath its crust. According to their simulations, this layer is 15 km (9 mi) thick sandwiched between the core and the mantle hundreds of miles beneath the surface. While this makes the diamonds inaccessible (for now, at least), these findings could have implications for theories about the formation and evolution of rocky planets.

July 25, 2024July 25, 2024 by Matt Williams

Planetary Habitability Depends on its Star’s Magnetic Field

Earth's magnetosphere is the region defined by our planet's magnetic field. Image Credit: NASA

The extrasolar planet census recently passed a major milestone, with 5500 confirmed candidates in 4,243 solar systems. With so many exoplanets available for study, astronomers have learned a great deal about the types of planets that exist in our galaxy and have been rethinking several preconceived notions. These include the notion of “habitability” and whether Earth is the standard by which this should be measured – i.e., could there be “super habitable” exoplanets out there? – and the very concept of the circumsolar habitable zone (CHZ).

Traditionally, astronomers have defined habitable zones based on the type of star and the orbital distance where a planet would be warm enough to maintain liquid water on its surface. But in recent years, other factors have been considered, including the presence of planetary magnetic fields and whether they get enough ultraviolet light. In a recent study, a team from Rice University extended the definition of a CHZ to include a star’s magnetic field. Their findings could have significant implications in the search for life on other planets (aka. astrobiology).

July 23, 2024July 23, 2024 by Matt Williams

The Ultraviolet Habitable Zone Sets a Time Limit on the Formation of Life

Artist's impression of the range of habitable zones for different types of stars. Credit: NASA/Kepler Mission/Dana Berry

The field of extrasolar planet studies has grown exponentially in the past twenty years. Thanks to missions like Kepler, the Transiting Exoplanet Survey Satellite (TESS), and other dedicated observatories, astronomers have confirmed 5,690 exoplanets in 4,243 star systems. With so many planets and systems available for study, scientists have been forced to reconsider many previously-held notions about planet formation and evolution and what conditions are necessary for life. In the latter case, scientists have been rethinking the concept of the Circumsolar Habitable Zone (CHZ).

By definition, a CHZ is the region around a star where an orbiting planet would be warm enough to maintain liquid water on its surface. As stars evolve with time, their radiance and heat will increase or decrease depending on their mass, altering the boundaries of the CHZ. In a recent study, a team of astronomers from the Italian National Institute of Astrophysics (INAF) considered how the evolution of stars affects their ultraviolet emissions. Since UV light seems important for the emergence of life as we know it, they considered how the evolution of a star’s Ultraviolet Habitable Zone (UHZ) and its CHZ could be intertwined.

July 20, 2024July 20, 2024 by Matt Williams

SpaceX Reveals the Beefed-Up Dragon That Will De-Orbit the ISS

Artist's impression of the U.S. Deorbit Vehicle currently being developed by SpaceX. Credit: NASA

The International Space Station (ISS) has been continuously orbiting Earth for more than 25 years and has been visited by over 270 astronauts, cosmonauts, and commercial astronauts. In January 2031, a special spacecraft designed by SpaceX – aka. The U.S. Deorbit Vehicle – will lower the station’s orbit until it enters our atmosphere and lands in the South Pacific. On July 17th, NASA held a live press conference where it released details about the process, including a first glance at the modified SpaceX Dragon responsible for deorbiting the ISS.

July 19, 2024July 19, 2024 by Matt Williams

Gaia Hit by a Micrometeoroid AND Caught in a Solar Storm

Artist impression of ESA's Gaia satellite observing the Milky Way. The background image of the sky is compiled from data from more than 1.8 billion stars. It shows the total brightness and colour of stars observed by Gaia — Artist impression of ESA's Gaia satellite observing the Milky Way (Credit : ESA/ATG medialab; Milky Way: ESA/Gaia/DPAC)

For over ten years, the ESA’s Gaia Observatory has monitored the proper motion, luminosity, temperature, and composition of over a billion stars throughout our Milky Way galaxy and beyond. This data will be used to construct the largest and most precise 3D map of the cosmos ever made and provide insight into the origins, structure, and evolutionary history of our galaxy. Unfortunately, this sophisticated astrometry telescope is positioned at the Sun-Earth L2 Lagrange Point, far beyond the protection of Earth’s atmosphere and magnetosphere.

As a result, Gaia has experienced two major hazards in recent months that could endanger the mission. These included a micrometeoroid impact in April that disrupted some of Gaia‘s very sensitive sensors. This was followed by a solar storm in May—the strongest in 20 years—that caused electrical problems for the mission. These two incidents could threaten Gaia‘s ability to continue mapping stars, planets, comets, asteroids, quasars, and other objects in the Universe until its planned completion date of 2025.

July 18, 2024July 18, 2024 by Matt Williams

ESA is Building a Mission to Visit Asteroid Apophis, Joining it for its 2029 Earth Flyby

ESA's Ramses mission to asteroid Apophis. Credit: ESA

According to the ESA’s Near-Earth Objects Coordination Center (NEOCC), 35,264 known asteroids regularly cross the orbit of Earth and the other inner planets. Of these, 1,626 have been identified as Potentially Hazardous Asteroids (PHAs), meaning that they may someday pass close enough to Earth to be caught by its gravity and impact its surface. While planetary defense has always been a concern, the comet Shoemaker-Levy 9 slamming into Jupiter in 1994 sparked intense interest in this field.

In 2022, NASA’s Double-Asteroid Redirect Test (DART) mission successfully tested the kinetic impact method when it collided with Dimorphos, the small asteroid orbiting Didymos. Today, the ESA Space Safety program is taking steps to test the next planetary defense mission – the Rapid Apophis Missin for Space Safety (RAMSES). In 2029, RAMSES will rendezvous with the Near Earth Asteroid (NEA) 99942 Apophis and accompany it as it makes a very close (but safe) flyby of Earth in 2029. The data it collects will help scientists improve our ability to protect Earth from similar objects that could pose an impact risk.