Featured Archives

June 28, 2023June 28, 2023 by Matt Williams

Two New Space Telescopes Will Bring Dark Energy Into Focus

High-resolution illustration of the Euclid and Roman spacecraft against a starry background. Credits: NASA’s Goddard Space Flight Center, ESA/ATG medialab

Since the 1990s, thanks to observations by the venerable Hubble Space Telescope (HST), astronomers have contemplated the mystery of cosmic expansion. While scientists have known about this since the late-1920s and early-30s, images acquired by Hubble‘s Ultra Deep Fields campaign revealed that the expansion has been accelerating for the past six billion years! This led scientists to reconsider Einstein’s theory that there is an unknown force in the Universe that “holds back gravity,” which he named the Cosmological Constant. To astronomers and cosmologists today, this force is known as “Dark Energy.”

However, not everyone is sold on the idea of Dark Energy, and some believe that cosmic expansion could mean there is a flaw in our understanding of gravity. In the near future, scientists will benefit from next-generation space telescopes to provide fresh insight into this mysterious force. These include the ESA’s Euclid mission, scheduled for launch this July, and NASA’s Nancy Grace Roman Space Telescope (RST), the direct successor to Hubble that will launch in May 2027. Once operational, these space telescopes will investigate these competing theories to see which holds up.

June 27, 2023June 27, 2023 by Matt Williams

Reusable Rockets Could Fly Back to Their Launch Sites With Wings

The two architectures (top to bottom), "fly-back" and "glide-back" configurations. Credit: Balesdant, M., et al. (2023)

Reusable launch vehicles have been a boon for the commercial space industry. By recovering and refurbishing the first stages of rockets, launch providers have dramatically reduced the cost of sending payloads and even crew to space. Beyond first-stage boosters, there are efforts to make rockets entirely reusable, from second stages to payload fairings. There are currently multiple strategies for booster recovery, including mid-air retrieval using helicopters and nets. Still, the favored method involves boosters returning to a landing pad under their own power (the boost-back and landing maneuver).

This strategy requires additional rocket propellant for the booster to land again, which comes at the expense of payload mass and performance for the ascent mission. As an alternative, researchers from the National Office Of Aerospace Studies And Research (ONERA) propose two new types of strategies that would allow boosters to return to their launch site. These are known as “glide-back” and “fly-back” architectures, both of which involve boosters with lifting surfaces (fins and wings) performing vertical takeoff and horizontal landing (VTVL) maneuvers.

June 26, 2023June 26, 2023 by Matt Williams

Mars Lacks a Planet-Wide Magnetosphere, but it Does Have Pockets of Magnetism

Mars has magnetized rocks in its crust that create localized, patchy magnetic fields (left). In the illustration at right, we see how those fields extend into space above the rocks. At their tops, auroras can form. Credit: NASA

The Zhurong rover has operated on the surface of Mars for over a year since it deployed on May 22nd, 2021. Before the rover suspended operations on May 20th, 2022, due to the onset of winter and the approach of seasonal sandstorms, Zhurong managed to traverse a total distance of 1.921 km (1.194 mi). During the first kilometer of this trek, the rover obtained vital data on Mars’ extremely weak magnetic fields. According to a new study by researchers from the Chinese Academy of Science (CAS), these readings indicate that the magnetic field is extremely weak beneath the rover’s landing site.

June 26, 2023June 26, 2023 by Matt Williams

Germany is Building a Tiny Rover That Will Roam the Surface of Phobos

Artist's impression of the IDEFIX rover on Phobos, with the MMX spacecraft in the background. Credit: DLR

At this very moment, eleven robotic missions are operating in orbit or on the surface of Mars, more than at any point during the past sixty years. These include the many orbiters surveying the Red Planet from orbit, the handful of landers and rovers, and one helicopter (Ingenuity) studying the surface. In the coming years, many more are expected, reflecting the growing number of nations participating in the exploration process. Once there, they will join in the ongoing search for clues about the planet’s formation, evolution, and possible evidence that life once existed there.

However, there’s also the mystery concerning the origin of Phobos and Deimos, Mars’ two satellites. While scientists have long suspected that these two moons began as asteroids kicked from the Main Belt that were captured by Mars’ gravity, there is no scientific consensus on this point. This is the purpose of the Martian Moons eXploration (MMX) mission currently under development by the Japan Aerospace Exploration Agency (JAXA), which will explore both moons with the help of a Phobos rover provided by the German Aerospace Center (DLR) and the French National Center of Space Studies (CNES).

June 21, 2023June 21, 2023 by Matt Williams

Bringing the Gift of Hope to Ukrainian Kids through Astronomy

Earthlings Hub is bringing education and counseling services to orphans and refugees in Ukraine, Credit: Earthlings Hub

The war in Ukraine has taken a terrible toll, and the damage extends far from the shifting battle lines. In addition to the many soldiers and civilians who’ve died, over 2.5 million children have been displaced within the country. The war has also exacerbated the problems of orphaned children, who are especially vulnerable in urban areas where the fighting has been most intense. Ensuring these children and their families can get adequate food and medical care is always challenging. Ensuring they have access to education and counseling services so their lives are not severely interrupted is even more so.

But there’s also the need for inspiration and hope for the future, which becomes all the more important in times of war and displacement. This is the purpose of Earthlings Hub, a non-profit organization dedicated to bringing astronomy and science education to refugee and orphan children in Ukraine. Founded in 2022 by members of the Blue Marble Space Institute of Science (BMSIS), Earthlings Hub is made up of scientists, teachers, and psychologists working to provide students with access to scientific research, equipment, and an inquiry-based educational program that goes beyond the standard school curriculum.

June 20, 2023June 20, 2023 by Matt Williams

JWST Glimpses the Cosmic Dawn of the Universe

This still image shows the timeline running from the Big Bang on the right, towards the present on the left. In the middle is the Reionization Period where the initial bubbles caused the cosmic dawn. Credit: NASA SVS

The James Webb Space Telescope (JWST) continues to push the boundaries of astronomy and cosmology, the very job it was created for. First conceived during the 1990s, and with development commencing about a decade later, the purpose of this next-generation telescope is to pick up where Spitzer and the venerable Hubble Space Telescope (HST) left off – examining the infrared Universe and looking farther back in time than ever before. One of the chief objectives of Webb is to observe high-redshift (high-Z) galaxies that formed during Cosmic Dawn.

This period refers to the Epoch of Reionization, where the first galaxies emitted large amounts of ultraviolet (UV) photons that ionized the neutral hydrogen that made up the intergalactic medium (IGM), causing the Universe to become transparent. The best way to measure the level of star formation is the H-alpha emission line, which is visible in the mid-infrared spectrum for galaxies with high redshifts. Using data from the Mid-Infrared Instrument (MIRI), an international team of researchers was able to resolve the H-alpha line and observe galaxies with redshift values higher than seven (z>7) for the first time.

June 18, 2023June 18, 2023 by Matt Williams

Astronomers See the Same Supernova Four Times Thanks to a Gravitational Lens

A gravitational lens caused by a galaxy in the foreground leading to an "Einstein Cross." Credit: NASA/ESA/STScI

Measuring cosmic distances is challenging, and astronomers rely on multiple methods and tools to do it – collectively referred to as the Cosmic Distance Ladder. One particularly crucial tool is Type Ia supernovae, which occur in binary systems where one star (a white dwarf) consumes matter from a companion (often a red giant) until it reaches the Chandrasekhar Limit and collapses under its own mass. As these stars blow off their outer layers in a massive explosion, they temporarily outshine everything in the background.

In a recent study, an international team of researchers led by Ariel Goobar of the Oskar Klein Centre at Stockholm University discovered an unusual Type Ia supernova, SN Zwicky (SN 2022qmx). In an unusual twist, the team observed an “Einstein Cross,” an unusual phenomenon predicted by Einstein’s Theory of General Relativity where the presence of a gravitational lens in the foreground amplifies light from a distant object. This was a major accomplishment for the team since it involved observing two very rare astronomical events that happened to coincide.

June 15, 2023June 15, 2023 by Matt Williams

Pulsars Could Help Map the Black Hole at the Center of the Milky Way

The Atacama Large Millimeter/submillimeter Array (ALMA) looked at Sagittarius A*, (image of Sag A* by the EHT Collaboration) to study something bright in the region around Sag A*. Credit: ESO/José Francisco Salgado.

The Theory of General Relativity (GR), proposed by Einstein over a century ago, remains one of the most well-known scientific postulates of all time. This theory, which explains how spacetime curvature is altered in the presence of massive objects, remains the cornerstone of our most widely-accepted cosmological models. This should come as no surprise since GR has been verified nine ways from Sunday and under the most extreme conditions imaginable. In particular, scientists have mounted several observation campaigns to test GR using Sagittarius A* (Sgr A*), the supermassive black hole at the center of the Milky Way.

Last year, the Event Horizon Telescope (EHT) – an international consortium of astronomers and observatories – announced they had taken the first images of Sag A*, which came just two years after the release of the first-ever images of an SMBH (M87). In 2014, the European members of the EHT launched another initiative known as BlackHoleCam to gain a better understanding of SMBHs using a combination of radio imaging, pulsar observations, astrometry, and GR. In a recent paper, the BHC initiative described how they tested GR by observing pulsars orbiting Sgr A*.

June 15, 2023June 16, 2023 by David Dickinson

Startup PLD Space to Launch Europe’s First Reusable Rocket

PLD Space could launch its suborbital Miura-1 rocket this month.

Update: Game on… PLD Space has announced that they will attempt to launch Miura-1 tonight. The live webcast starts on June 17th (Saturday local time) at 1:00 AM Central European Time (11:00 PM Friday night on June 16th Universal Time, and 7:00 PM Eastern Daylight Saving Time), and the eight hour launch window begins at 2:00 AM CET/00:00UT/8:00 PM EDT.

A small space startup with big ambitions may be joining the private spaceflight club soon. This summer, Elche Spain-based PLD Space is set to carry out the first test launch of their single stage, suborbital Miura-1 rocket.

June 14, 2023June 14, 2023 by Matt Williams

A Day on Earth Used to Only Be 19 Hours

A full disk view of the Earth, courtesy of Meteosat-I 1. Credit: ESA/Meteosat

On Earth, a single solar day lasts 24 hours. That is the time it takes for the Sun to return to the same place in the sky as the day before. The Moon, Earth’s only natural satellite, takes about 27 days to complete a single circuit around our planet and orbits at an average distance of 384,399 km (~238,854.5 mi). Since time immemorial, humans have kept track of the Sun, the Moon, and their sidereal and synodic periods. To the best of our knowledge, the orbital mechanics governing the Earth-Moon system have been the same, and we’ve come to take them for granted.

But there was a time when the Moon orbited significantly closer to Earth, and the average day was much shorter than today. According to a recent study by a pair o researchers from China and Germany, an average day lasted about 19 hours for one billion years during the Proterozoic Epoch – a geological period during the Precambrian that lasted from 2.5 billion years to 541 million years ago. This demonstrates that rather than gradually increasing over time (as previously thought), the length of a day on Earth remained constant for an extended period.