Chinese Academy of Sciences Archives

March 3, 2024March 3, 2024 by Matt Williams

A Giant Gamma-Ray Bubble is a Source of Extreme Cosmic Rays

An artist's depiction of a gamma-ray burst's relativistic jet full of very-high-energy photons breaking out of a collapsing star. Credit: DESY, Science Communication Lab

Gamma-ray bursts (GRBs) are one of the most powerful phenomena in the Universe and something that astronomers have been studying furiously to learn more about their origins. In recent years, astronomers have set new records for the most powerful GRB ever observed – this includes GRB 190114C, observed by the Hubble Space Telescope in 2019, and GRB 221009A, detected by the Gemini South telescope in 2022. The same is true for high-energy cosmic rays that originate from within the Milky Way, whose origins are still not fully understood.

In a recent study, members of China’s Large High Altitude Air Shower Observatory (LHAASO) Collaboration discovered a massive gamma-ray burst (designated GRB 221009A) in the Cygnus star-forming region that was more powerful than 10 peta-electronvolts (PeV, 1PeV=10¹⁵eV), over ten times the average. In addition to being the brightest GRB studied to date, the team was able to precisely measure the energy spectrum of the burst, making this the first time astronomers have traced cosmic rays with this energy level back to their source.

August 12, 2023August 12, 2023 by Matt Williams

Astronomers Find a Newly-Forming Quadruple-Star System

This artist’s impression shows the orbits of the objects in the HR 6819 triple system. Credit: ESO/L. Calçada

In a surprising find, the international ALMA Survey of Orion Planck Galactic Cold Clumps (ALMASOP) team recently observed a young quadruple star system within a star-forming region in the Orion constellation. The discovery was made during a high-resolution survey of 72 dense cores in the Orion Giant Molecular Clouds (GMCs) using the Atacama Large Millimeter/submillimeter Array (ALMA) in Chile. These observations provide a compelling explanation for the origins and formation mechanisms of binary and multiple-star systems.

May 7, 2023May 7, 2023 by Matt Williams

China's Mars Rover Finds Recent Evidence of Water Near the Equator

China's Zhurong rover on Mars — An image from China's Zhurong rover shows spacecraft hardware in the foreground and Martian terrain in the background. (Credit: CNSA)

The surface of Mars is a pretty desolate place at first glance. The soil is many times as dry as the driest desert on planet Earth, the temperatures swing from one extreme to the other, and the air is incredibly thin and toxic. And yet, there’s ample evidence that the planet was once much warmer and wetter, with lots of flowing and standing water on its surface. Over time, as Mars’ atmosphere was slowly stripped away, much of this water was lost to space, and what remains is largely concentrated around the poles as glacial ice and permafrost.

For years, space agencies have been sending robotic landers, rovers, orbiters, and aerial vehicles to Mars to learn more about when this transition took and how long it took. According to China’s Tianwen-1 mission, which includes the Zhurong rover, there may have been liquid water on the Martian surface later than previously thought. According to new research from the Chinese Academy of Sciences (CAS), the Zhurong rover observed salt-rich dunes in the Utopia Planitia region that showed cracks and crusts, indicating the possible presence of water as recently as a few hundred thousand years ago.

March 29, 2023August 25, 2023 by Matt Williams

China Hints at its Goals for a Lunar Base

Visualization of the ILRS, from the CNSA Guide to Partnership (June 2021). Credit: CNSA

In June 2021, China announced it was partnering with Russia to launch a lunar exploration program that would rival NASA’s Artemis Program. This program would include robotic landers, orbiters, and crewed missions that would culminate with the creation of an outpost around the Moon’s southern polar region – the International Lunar Research Station (ILRS). While the details are still scant, periodic updates have provided a “big-picture” idea of what this lunar outpost will look like.

Case in point, at a recent national space conference, a team of scientists from the Chinese Academy of Sciences (CAS) presented a list of objectives for the ILRS. According to China Science Daily, these objectives will include Moon-based astronomy, Earth observation, and lunar in-situ resource utilization (ISRU). In addition, the CAS scientists indicated that China plans to establish a basic model for a lunar research station based on two planned exploration missions by 2028, which will subsequently expand into an international base.

January 12, 2023January 12, 2023 by Matt Williams

Astronomers use the World's Biggest Radio Telescope to map new Features of the Milky Way

Artist impression of a fast radio burst. Credit: Danielle Futselaar

Despite everything astronomers have learned about the nature and structure of galaxies, there are still mysteries about the Milky Way. The reason for this is simple: since we are embedded in the Milky Way’s disk, we have difficulty mapping it and observing it as a whole. It’s also very challenging to observe the center of the galaxy, what lies beyond it, and features in the disk itself because of all the gas and dust between stars- the Interstellar Medium (ISM). However, by observing the Milky Way in the non-visible spectrum (radio, x-ray, gamma-ray, etc.), astronomers can see more of what’s out there.

There’s also the spectral line that corresponds to the emission frequency (1420 MHz) of cold neutral hydrogen gas (HI), which makes up the majority of the ISM. Using the Five-hundred-meter Aperture Spherical Telescope (FAST) – the most powerful radio telescope in the world near Guizhou, China – a team of scientists located more than 500 new faint pulsars. During the survey, the team simultaneously recorded the spectral line data with high spectral and spatial resolution, making it an extremely valuable resource for studying the structure of the Milky Way Galaxy and the life cycle of its stars.

November 3, 2022November 3, 2022 by Matt Williams

The Moon had Volcanoes More Recently Than Previously Believed

New measurements of lunar rocks have demonstrated that the ancient moon generated a dynamo magnetic field in its liquid metallic core (innermost red shell). The results raise the possibility of two different mechanisms — one that may have driven an earlier, much stronger dynamo, and a second that kept the moon’s core simmering at a much slower boil toward the end of its lifetime. Credit: Hernán Cañellas/Benjamin Weiss

Fifty years ago, NASA and the Soviet space program conducted the first sample-return missions from the Moon. This included lunar rocks brought back to Earth by the Apollo astronauts and those obtained by robotic missions that were part of the Soviet Luna Program. The analysis of these rocks revealed a great deal about the Moon’s composition, formation, and geological history. In particular, scientists concluded that the rocks were formed from volcanic eruptions more than three billion years ago.

In recent years, there has been a resurgence in lunar exploration as NASA and other space agencies have sent robotic missions to the Moon (in preparation for crewed missions). For instance, China has sent multiple orbiters, landers, and rovers to the Moon as part of the Chang’e program, including sample-return missions. A new study led by planetary scientists from the Chinese Academy of Sciences (CAS) analyzed samples obtained by the Chang’e-5 rover dated to two billion years ago. Their research could provide valuable insight into how young volcanism shaped the lunar surface.

May 21, 2022May 21, 2022 by Matt Williams

The Closeby Habitable Exoplanet Survey (CHES) Could Detect Exoplanets Within a few Dozen Light-Years of Earth Using Astrometry

Artist's concept of Earth-like exoplanets, which (according to new research) need to strike the careful balance between water and landmass. Credit: NASA

As of this article’s writing, NASA has indicated that 5,030 extrasolar planets have been confirmed in 3,772 systems, with another 8,974 candidates awaiting confirmation. With next-generation instruments like the James Webb Space Telescope (JWST) coming online, the number and diversity of confirmed exoplanets are expected to grow exponentially. In particular, astronomers anticipate that the number of known terrestrial planets and Super-Earths will drastically increase.

In the coming years, the opportunities for exoplanet studies will increase considerably as thousands more are discovered using various methods. In a recent study, a team led by the Chinese Academy of Sciences (CAS) described a new space-telescope concept known as the Closeby Habitable Exoplanet Survey (CHES). This proposed observatory will search for Earth-like planets in the habitable zones (HZs) of Sun-like stars within approximately 33 light-years (10 parsecs) using a method known as micro-arcsecond relative astrometry.

October 19, 2021October 19, 2021 by Matt Williams

Something Really Wants our Attention. One Object Released 1,652 Fast Radio Bursts in 47 Days

The energetic phenomena known as Fast Radio Bursts (FRBs) are one of the greatest cosmic mysteries today. These mysterious flashes of light are visible in the radio wave part of the spectrum and usually last only a few milliseconds before fading away forever. Since the first FRB was observed in 2007, astronomers have looked forward to the day when instruments of sufficient sensitivity would be able to detect them regularly.

That day has arrived with the completion of the 500-Meter FAST Radio Telescope (aka. Tianyan, “Eye of Heaven”). Since it commenced operations, this observatory has vastly expanded the number of detected FRBs. In fact, according to research led by the National Astronomical Observatories of the Chinese Academy of Sciences (NAO/CAS), the observatory detected a total of 1,652 independent bursts from a single source in 47 days.

January 4, 2021January 4, 2021 by Matt Williams

Astronomers Discover Hundreds of High-Velocity Stars, Many on Their Way Out of the Milky Way

Since discovering the first one in 2005, astronomers have found hundreds of stars that travel fast enough that they could escape the Milky Way as HVSs. Image Credit: NAOC/Kong Xiao

Within our galaxy, there are thousands of stars that orbit the center of the Milky Way at high velocities. On occasion, some of them pick up so much speed that they break free of our galaxy and become intergalactic objects. Because of the extreme dynamical and astrophysical processes involved, astronomers are most interested in studying these stars – especially those that are able to achieve escape velocity and leave our galaxy.

However, an international team of astronomers led from the National Astronomical Observatories of China (NAOC) recently announced the discovery of 591 high-velocity stars. Based on data provided by the Large Sky Area Multi-Object Fiber Spectroscopic Telescope (LAMOST) and the ESA’s Gaia Observatory, they indicated that 43 of these stars are fast enough to escape the Milky Way someday.

February 6, 2019March 3, 2020 by Matt Williams

The Milky Way is Actually Warped

Artist’s impression of the warped and twisted Milky Way disk. Credit: Chen Xiaodian/Kavli Institute of Astronomy and Astrophysics

For centuries, astronomers have been studying the Milky Way in order to get a better understanding of its size and structure. And while modern instruments have yielded invaluable observations of our galaxy and others (which have allowed astronomers to gain a general picture of what it looks like), a truly accurate model of our galaxy has been elusive.

For example, a recent study by a team of astronomers from National Astronomical Observatories of Chinese Academy of Sciences (NAOC) has shown that the large-scale structure of the Milky Way is quite warped. Based on their findings, it appears that this effect becomes increasingly evident the farther away one ventures from the core.