Featured Archives

December 19, 2022January 28, 2023 by Matt Williams

Hubble and Spitzer Team up to Find a Pair of Waterworld Exoplanets

Artist’s impression of a water world, where half of its mass consists of water. Just like our Moon, the planet is bound to its star by tidal forces and always shows the same face to its host star. Credit: Pilar Montañés

As of December 19th, 2022, 5,227 extrasolar planets have been confirmed in 3,908 systems, with over 9,000 more awaiting confirmation. While most of these planets are Jupiter- or Neptune-sized gas giants or rocky planets many times the size of Earth (Super-Earths), a statistically significant number have been planets where water makes up a significant part of their mass fraction – aka. “water worlds.” These planets are unlike anything we’ve seen in the Solar System and raise several questions about planet formation in our galaxy.

In a recent study, an international team led by researchers from the University of Montreal’s Institute for Research on Exoplanets (iREx) found evidence of two water worlds in a single planetary system located about 218 light-years away in the constellation Lyra. Based on their densities, the team determined that these exoplanets (Kepler-138c and Kepler-138d) are lighter than rocky “Earth-like” ones but heavier than gas-dominated ones. The discovery was made using data from NASA’s now-retired Spitzer Space Telescope and the venerable Hubble Space Telescope.

December 19, 2022December 19, 2022 by Matt Williams

Gravitational Wave Observatories Could Search for Warp Drive Signatures

Artist's impression of a Dyson Sphere. The construction of such a massive engineering structure would create a technosignature that could be detected by humanity. Credit: SentientDevelopments.com/Eburacum45

In 2016, scientists at the Laser Interferometer Gravitational-Wave Observatory (LIGO) announced that they had made the first confirmed detection of gravitational waves (GWs). This discovery confirmed a prediction made a century before by Einstein and his Theory of General Relativity and opened the door to a whole new field of astrophysical research. By studying the waves caused by the merger of massive objects, scientists could probe the interior of neutron stars, detect dark matter, and discover new particles around supermassive black holes (SMBHs).

According to new research led by the Advanced Propulsion Laboratory at Applied Physics (APL-AP), GWs could also be used in the Search for Extraterrestrial Intelligence (SETI). As they state in their paper, LIGO and other observatories (like Virgo and KAGRA) have the potential to look for GWs created by Rapid And/or Massive Accelerating spacecraft (RAMAcraft). By combining the power of these and next-generation observatories, we could create a RAMAcraft Detection And Ranging (RAMADAR) system that could probe all the stars in the Milky Way (100 to 200 billion) for signs of warp-drive-like signatures.

December 16, 2022December 16, 2022 by Matt Williams

Aztecs Used an Extremely Accurate Solar Observatory to Manage Their Farming

Stone causeway atop Mount Tlaloc, Mexico. Credit: Ben Messiner/UCR

Pre-Columbian Mexico (or Mesoamerica) hosted one of the largest civilizations and populations in the world. The most well-known and dominant of these civilizations (prior to the arrival of the Conquistadors) were the Aztecs (or Mexica). Their empire, known as the Triple Alliance, was centered around Lake Texcoco and consisted of the major cities Tenochtitlan, Texcoco, and Tlacopan. In addition to engineering massive temples, aqueducts, canal systems, and estuaries, the Aztecs are renowned for being accomplished astronomers and agronomists.

At the height of their power, the Aztec Empire supported a population of up to 3 million in the Valley of Mexico, and many of their largest cities had populations exceeding 100,000. This was not easy, given that the region is characterized by arid springs followed by winter monsoons. According to recent research by the University of California Riverside (UCR), the Aztecs used mountain alignments as a solar observatory to create an accurate agricultural calendar. This allowed their farmers to produce enough food to feed one of the most densely-populated regions on Earth.

December 15, 2022December 27, 2022 by Matt Williams

Birds use Dynamic Soaring to Pick Up Velocity. We Could Use a Similar Trick to Go Interstellar

The Solar Sail demonstration mission. Credit: NASA

To stand on a coastal shore and watch how eagles, ravens, seagulls, and crows take flight in high winds. it’s an inspiring sight, to be sure. Additionally, it illustrates an important concept in aerial mechanics, like how the proper angling of wings can allow birds to exploit differences in wind speed to hover in mid-air. Similarly, birds can use these same differences in wind speed to gain bursts of velocity to soar and dive. These same lessons can be applied to space, where spacecraft could perform special maneuvers to pick up bursts of speed from “space weather” (solar wind).

This was the subject of a recent study led by researchers from McGill University in Montreal, Quebec. By circling between regions of the heliosphere with different wind speeds, they state, a spacecraft would be capable of “dynamic soaring” the same way avian species are. Such a spacecraft would not require propellant (which makes up the biggest mass fraction of conventional missions) and would need only a minimal power supply. Their proposal is one of many concepts for low-mass, low-cost missions that could become interplanetary (or interstellar) explorers.

December 13, 2022December 13, 2022 by Matt Williams

Astronomers Spot Three Interacting Systems with Twin Discs

Artist's conceptualization of the dusty TYC 8241 2652 system as it might have appeared several years ago when it was emitting large amounts of excess infrared radiation. Credit: Gemini Observatory/AURA artwork by Lynette Cook. https://www.gemini.edu/node/11836

According to the most widely-accepted theory about star formation (Nebular Hypothesis), stars and planets form from huge clouds of dust and gas. These clouds undergo gravitational collapse at their center, leading to the birth of new stars, while the rest of the material forms disks around it. Over time, these disks become ring structures that accrete to form systems of planets, planetoids, asteroid belts, and Kuiper belts. For some time, astronomers have questioned how interactions between early stellar environments may affect their formation and evolution.

For instance, it has been theorized that gravitational interactions with a passing star or shock waves from a supernova might have triggered the core collapse that led to our Sun. To investigate this possibility, an international team of astronomers observed three interacting twin disc systems using the Spectro-Polarimetric High-contrast Exoplanet REsearch (SPHERE) on the ESO’s Very Large Telescope (VLT). Their findings show that due to their dense stellar environments, gravitational encounters between early-stage star systems play a significant role in their evolution.

December 12, 2022December 12, 2022 by Matt Williams

Orion Splashes Down in the Pacific Ocean, Completing the Artemis I Mission

NASA’s Orion spacecraft for the Artemis I mission splashed down in the Pacific Ocean at 9:40 a.m. PST on Sunday, Dec. 11, after a 25.5 day mission to the Moon. Credit: NASA

On December 11th, at 09:40 a.m. PST (12:40 p.m. EST), NASA’s Artemis I mission splashed down in the Pacific Ocean off the coast of Baja California. The return of the uncrewed Orion spacecraft marks the end of the Artemis Program’s inaugural mission, which launched on November 16th and validated the spacecraft and its heavy launch vehicle – the Space Launch System (SLS). During its 25.5-day circumlunar flight, the Orion spacecraft traveled more than 2.25 million km (1.4 million mi) and flew beyond the Moon’s orbit, establishing a new distance record.

December 9, 2022December 10, 2022 by Matt Williams

NASA Tests a Solar Sail Segment of its Enormous Solar Cruiser Mission

Artist's concept of the Solar Cruiser mission. Credit: NASA

A team led by NASA’s Marshall Space Flight Center (MSFC) was recently selected to develop a solar sail spacecraft that would launch sometime in 2025. Known as the Solar Cruiser, this mission of opportunity measures 1653 m² (~17790 ft²) in area and is about the same thickness as a human hair. Sponsored by the Science Mission Directorate’s (SMD) Heliophysics Division, this technology demonstrator will integrate several new solar sail technologies developed by various organizations to mature solar sail technology for future missions.

In a recent video released by NASA, we see engineers and industry partners at the MSFC in Huntsville, Alabama, unfurling a segment of the prototype solar sail. The video, taken on October 13th, shows how the teams used two 30.5 m (100-foot) lightweight composite booms to unfurl a 400 m² (4,300 ft²) quadrant of the solar sail prototype for the first time. Once realized, the Solar Cruiser demonstrator will validate technologies that enable future missions to study the Sun, its interaction with Earth, and its extended atmosphere (aka. heliosphere).

December 9, 2022December 12, 2022 by Matt Williams

A new 3D map of the Milky Way Uses close to 66,000 Stars and Reveals New Details About the Shape of our Galaxy

The warping of the Milky Way disk. Credit: University of Warsaw

In the 17th century, Galileo Galilee aimed his telescope at the stars and demonstrated (for the first time) that the Milky Way was not a nebulous band but a collection of distant stars. This led to the discovery that our Sun was merely one of the countless stars in a much larger structure: the Milky Way Galaxy. By the 18th century, William Herschel became the first astronomer to create a map that attempted to capture the shape of the Milky Way. Even after all that time and discovery, astronomers are still plagued by the problem of perspective.

While we have been able to characterize galaxies we see across the cosmos with relative ease, it is difficult for astronomers to study the size, shape, and population of the Milky Way because of how our Solar System is embedded in its disk. Luckily, there are methods to circumvent this problem of perspective, which have provided astronomers with clues to these questions. In a recent paper, a team from the Astronomical Observatory at the University of Warsaw (AstroUW) used a large collection of Mira variable stars to trace the shape of the Milky Way, which yielded some interesting results!

December 8, 2022December 8, 2022 by Matt Williams

There's a Giant Magma Plume on Mars, Bulging the Surface out Across a Vast Region

Lava flows in Mars' Elysium Planitia region have left a rather good likeness of a woolly mammoth or elephant. The region is known for some of the planet's youngest lavas - this one may formed in the past 100 million years.

Billions of years ago, Mars was a much different place than it is today. Its atmosphere was thicker and warmer, liquid water flowed on its surface, and the planet was geologically active. Due to its lower gravity, this activity led to the largest volcanoes in the Solar System (Olympus Mons and the Thetis Mons region) and the longest, deepest canyon in the world (Valles Marineris). Unfortunately, Mars’ interior began to cool rapidly, its inner core solidified, and geological activity largely stopped. For some time, geologists have believed that Mars was essentially “dead” in the geological sense.

However, recent studies have provided seismic and geophysical evidence that Mars may still be “slightly alive.” In a recent study, scientists from the University of Arizona (ASU) challenged conventional views of Martian geodynamic evolution by discovering evidence of an active mantle plume pushing its way through the crust, causing earthquakes and volcanic eruptions. Combined with some serious marsquakes recorded by NASA’s InSight lander, these finding suggests that there is still some powerful volcanic action beneath the surface of Mars.

December 7, 2022December 7, 2022 by Matt Williams

“Early Dark Energy” Could Explain the Crisis in Cosmology

A diagram of the evolution of the observable universe. The Dark Ages are the object of study in this new research, and were preceded by the CMB, or Afterglow Light Pattern. By NASA/WMAP Science Team - Original version: NASA; modified by Cherkash, Public Domain, https://commons.wikimedia.org/w/index.php?curid=11885244 — A diagram of the evolution of the observable universe. Credit: NASA/WMAP/Wikimedia

In 1916, Einstein finished his Theory of General Relativity, which describes how gravitational forces alter the curvature of spacetime. Among other things, this theory predicted that the Universe is expanding, which was confirmed by the observations of Edwin Hubble in 1929. Since then, astronomers have looked farther into space (and hence, back in time) to measure how fast the Universe is expanding – aka. the Hubble Constant. These measurements have become increasingly accurate thanks to the discovery of the Cosmic Microwave Background (CMB) and observatories like the Hubble Space Telescope.

Astronomers have traditionally done this in two ways: directly measuring it locally (using variable stars and supernovae) and indirectly based on redshift measurements of the CMB and cosmological models. Unfortunately, these two methods have produced different values over the past decade. As a result, astronomers have been looking for a possible solution to this problem, known as the “Hubble Tension.” According to a new paper by a team of astrophysicists, the existence of “Early Dark Energy” may be the solution cosmologists have been looking for.