The purpose of this workshop is to identify activities that will help prepare for missions to Mars by the 2030s. In particular, the workshop sought to address how a sustainable program of human Martian exploration can be achieved. The highlights of this event were recently shared with the release of the Achieve Mars (AM) IX Report, which established priorities and science objectives for future missions to Mars. The authors also made several recommendations for how cutting-edge technologies could play a role, how the health and safety of astronauts can be assured, and how Mars and Earth can be protected from possible contamination.
Hypervelocity stars (HVS) certainly live up to their name, traveling thousands of kilometers per second or a fraction of the speed of light (relativistic speeds). These speed demons are thought to be the result of galactic or black hole mergers, globular clusters kicking out members, or binary pairs where one star is kicked out when the other goes supernova. Occasionally, these stars are fast enough to escape our galaxy and (in some cases) take their planetary systems along for the ride. This could have drastic implications for our theories of how life could be distributed throughout the cosmos (aka. panspermia theory).
There are thousands of these stars in our galaxy, and tracking them has become the task of cutting-edge astrometry missions (like the ESA’s Gaia Observatory). In previous research, astronomers suggested that these stars could be used to determine the mass of the Milky Way. In a recent study from Leiden University in the Netherlands, Ph.D. candidate Fraser Evans showed how data on HVS could be used to probe the mysteries of the most extreme objects in our Universe – supermassive black holes (SMBHs) and the violent supernovae of massive stars.
Alpha Centauri is our closest stellar neighbor, a binary star system located just 4.376 light-years away. Despite its proximity, repeated astronomical surveys have failed to find hard evidence of extrasolar planets in this system. Part of the problem is that the system consists of two stars orbiting each other, which makes detecting exoplanets through the two most popular methods very challenging. In 2019, Breakthrough Initiatives announced they were backing a new project to find exoplanets next door – the Telescope for Orbit Locus Interferometric Monitoring of our Astronomical Neighbourhood (TOLIMAN, after the star’s ancient name in Arabic).
This low-cost mission concept was designed by a team from the University of Sydney, Australia, and aims to look for potentially-habitable exoplanets in the Alpha Centauri system using the Astrometry Method. This consists of monitoring a star’s apparent position in the sky for signs of wobble, indicating that gravitational forces (like planets) are acting on it. Recently, the University of Sydney signed a contract with EnduroSat, a leading microsatellites and space services provider, to provide the delivery system and custom-built minisatellite that will support the mission when it launches.
Fans of Star Trek were over the Moon when, in 2018, astronomers with the Dharma Planet Survey (DPS) announced the possible detection of 40 Eridani b, an extrasolar planet in the star system 40 Eridani. Located just 16.3 light-years away, this triple-star system happens to be where the planet Vulcan was located in the popular franchise. Based on radial velocity measurements of the system’s primary star (40 Eridani A), the discovery team estimated that “Vulcan” was a rocky planet several times the mass of Earth (a Super-Earth) with an orbital period of 42 days or so.
The existence of this exoplanet has remained a controversial subject ever since. A study released in 2021 concluded that the signal was a false positive, but the debate remained open. Now, according to a new study by an international team of researchers, the detection of 40 Eridani b was a false positive that astronomers mistook for an exoplanet. The study was part of an archival review of exoplanets to identify promising candidates for follow-up studies. So while “Vulcan” is currently off the table, these results could lead to other exciting discoveries in the coming years.
According to the most widely-accepted model of cosmology, the Universe began roughly 13.8 billion years ago with the Big Bang. As the Universe cooled, the fundamental laws of physics (the electroweak force, the strong nuclear force, and gravity) and the first hydrogen atoms formed. By 370,000 years after the Big Bang, the Universe was permeated by neutral hydrogen and very few photons (the Cosmic Dark Ages). During the “Epoch of Reionization” that followed, the first stars and galaxies formed, reoinizing the neutral hydrogen and causing the Universe to become transparent.
For astronomers, the Epoch of Reionization still holds many mysteries, like when certain heavy elements formed. This includes the element carbon, a key ingredient in the formation of planets, an important element in organic processes, and the basis for life as we know it. According to a new study by the ARC Center of Excellence for All Sky Astrophysics in 3 Dimensions (ASTRO 3D), it appears that triply-ionized carbon (C iv) existed far sooner than previously thought. Their findings could have drastic implications for our understanding of cosmic evolution.
Over 13 billion years ago, the first galaxies in the Universe formed. They were elliptical, with intermediate black holes (IMBHs) at their centers surrounded by a halo of stars, gas, and dust. Over time, these galaxies evolved by flattening out into disks with a large bulge in the middle. They were then drawn together by mutual gravitational attraction to form galaxy clusters, massive collections that comprise the large-scale cosmic structure. This force of attraction also led to mergers, where galaxies and their central black holes came together to create larger spiral galaxies with central supermassive black holes (SMBHs).
This process of mergers and assimilation (and their role in galactic evolution) is still a mystery to astronomers today since much of it took place during the early Universe, which is still very difficult to observe with existing telescopes. Using data from NASA’s Chandra X-ray Observatory and the International Gemini Observatory, an international team of astronomers observed a lone distant galaxy that appears to have consumed all of its former companions. Their findings, which recently appeared in The Astrophysical Journal, suggest galaxies in the early Universe grew faster than previously thought.
“It is possible even with existing technology, if done in the most efficient ways. New methods are needed, but none goes beyond the range of present-day knowledge. The challenge is to bring the goal of space colonization into economic feasibility now, and the key is to treat the region beyond Earth not as a void but as a culture medium, rich in matter and energy. Then, in a time short enough to be useful, the exponential growth of colonies can reach the point at which the colonies can be of great benefit to the entire human race.”
-Gerard K. O’Neill, The Colonization of Space, 1974
During the 1960s and 70s, coinciding with the height of the Space Age, scientists pondered how human beings could one day live in space. Among the many benefits, the migration of humans and industry to other celestial bodies and orbiting habitats presented a possible solution to overpopulation and environmental degradation. As O’Neill suggested in his writings, the key was to make this migration an economically feasible venture. Given the renewed efforts to explore space that are now underway and the rise of commercial space (NewSpace), there is a growing sense that humanity’s migration to space is within reach – and even inevitable.
But to paraphrase famed British historian AJP Taylor, “nothing is inevitable until it happens.” In a new study, Cornell graduate researcher Morgan A. Irons and Norfolk Institute co-founder and executive director Lee G. Irons reviewed a century of scientific studies to develop the Pancosmorio (“World Limit”) theory. They concluded that specific life-sustaining conditions on Earth that are available nowhere else in the Solar System could be the very thing that inhibits our expansion into space. Without an Earth-like “self-restoring order, capacity, and organization,” they argue, space settlements would fail to be sustainable and collapse before long.
For years, China has been dropping hints about its Long March 9 (CZ-9) rocket, a three-stage super-heavy variant of the Long March family. This launch vehicle will reportedly be capable of transporting up to 150,000 kg (165 tons) to Low Earth Orbit (LEO) and 54,000 kg (59.5 tons) to a trans-lunar injection. On March 2nd, the China Academy of Launch Vehicle Technology (CALT) announced (via the Chinese social media platform Weixin) that it had finished building the first propellant tank for the CZ-9.
The news was accompanied by pictures that showed the finished tank and the many components that went into making it – and they are massive!
In the 1930s, astrophysicists theorized that at the end of their life cycle, particularly massive stars would collapse, leaving behind remnants of infinite mass and density. As a proposed resolution to Einstein’s field equations (for his Theory of General Relativity), these objects came to be known as “black holes” because nothing (even light) could escape them. By the 1960s, astronomers began to infer the existence of these objects based on the observable effects they have on neighboring objects and their surrounding environment.
Despite improvements in instruments and interferometry (which led to the first images of M87 and Sagittarius A*), the study of black holes still relies on indirect methods. In a recent study, a team of Japanese researchers identified an unusual cloud of gas that appears to have been elongated by a massive, compact object that it orbits. Since there are no massive stars in its vicinity, they theorize that the cloud (nicknamed the “Tadpole” because of its shape) orbits a black hole roughly 27,000 light-years away in the constellation Sagittarius.
Less than a year and a half into its primary mission, the James Webb Space Telescope (JWST) has already revolutionized astronomy as we know it. Using its advanced optics, infrared imaging, and spectrometers, the JWST has provided us with the most detailed and breathtaking images of the cosmos to date. But in the coming years, this telescope and its peers will be joined by another next-generation instrument: the Nancy Grace Roman Space Telescope (RST). Appropriately named after “the Mother of Hubble,” Roman will pick up where Hubble left off by peering back to the beginning of time.
Like Hubble, the RST will have a 2.4-meter (7.9 ft) primary mirror and advanced instruments to capture images in different wavelengths. However, the RST will also have a gigantic 300-megapixel camera – the Wide Field Instrument (WFI) – that will enable a field of view two-hundred times greater than Hubble’s. In a recent study, an international team of NASA-led researchers described a simulation they created that previewed what the RST could see. The resulting data set will enable new experiments and opportunities for the RST once it takes to space in 2027.