Astronomy

A unique crystalline compound soaks up CO2 with great efficiency

SpaceX is launching Starship on its 6th test flight, with another Super Heavy booster catch back at the rocket's Starbase, Texas launch tower. Watch the action live on Space.com.

Four southern giant hornets have been identified in northern Spain, leading to concerns that the species could harm native insects if it becomes widespread

Four southern giant hornets have been identified in northern Spain, leading to concerns that the species could harm native insects if it becomes widespread

Several populations of Mexican tetra fish that live in darkness have independently evolved to need hardly any sleep, but the reason why is a mystery

Several populations of Mexican tetra fish that live in darkness have independently evolved to need hardly any sleep, but the reason why is a mystery

Video: 00:04:31

The double-satellite Proba-3 is the most ambitious member yet of ESA’s Proba family of experimental missions. Two spacecraft will fly together as one, maintaining precise formation down to a single millimetre. One will block out the fiery disc of the Sun for the other, to enable prolonged observations of the Sun’s surrounding atmosphere, or ‘corona’, the source of the solar wind and space weather. Usually, the corona can only be glimpsed for a few minutes during terrestrial total solar eclipses. Proba-3 aims to reproduce such eclipses for up to six hours at a time, in a highly elliptical orbit taking it more than 60 000 km from Earth. The two spacecraft are being launched together by India’s PSLV-XL launcher from the Satish Dhawan Space Centre. Follow the mission’s deployment and commissioning, up to its first glimpse of the corona, in this overview video.

Most mathematicians have been reluctant to start working with artificial intelligence, but a new tool developed by researchers at Meta may change that

Most mathematicians have been reluctant to start working with artificial intelligence, but a new tool developed by researchers at Meta may change that

The 2024 China International Aviation and Aerospace Exhibition was held in Zhuhai last week – from November 12th to 17th, 2024. Since 1996, and with support from the Chinese aerospace industry, this biennial festival features actual products, trade talks, technological exchanges, and an air show. This year’s big highlight was China’s newly announced reusable space cargo shuttle, the Haolong (Chinese for “dragon”). According to chief designer Fang Yuanpeng, the spacecraft has entered the engineering phase and will be ready for space in the near future.

The Haolong shuttle is being developed by the Chengdu Aircraft Design and Research Institute, which has developed several Chinese fighter jets in the past. It has a large wingspan, measuring eight meters (26.25 ft) in width and about 10 meters (33 ft) long, with a high lift-to-drag ratio. From the image provided (above), the design is clearly inspired by the now-retired Space Shuttle and features the same type of payload bay with two bay doors. While the cargo shuttle has a comparable wingspan (8.7 m; 29 ft), it is significantly shorter than the Space Shuttle, which measured 56.1 m (184 ft) in length.

This makes the Haolong (in terms of size) more akin to the X-37B and China’s Shenlong spaceplane. Like these spaceplanes, the Haolong spacecraft will be autonomous and feature cutting-edge aviation technologies. The design was one of several concepts issued in response to a solicitation by the China Manned Space Agency (CMSA) for low-cost and commercial cargo spacecraft. These will provide logistical support for China’s Tiangong space station as it undergoes expansion in the coming years.

Artist’s impression of China’s reusable Shenlong spaceplane. Credit: China Aerospace Studies Institute

According to the state-owned news agency Xinhua, the winners of the solicitation were announced on October 29th. This included the CMSA’s Haolong shuttle and the Qingzhou spacecraft, an integrated cargo capsule submitted by the Innovation Academy for Microsatellites of the Chinese Academy of Sciences (IAMCAS). According to Lin Xiqiang, the deputy director of the CMSA, both companies won contracts for the flight verification phase of their proposals. According to Fang, the space shuttle Haolong will launch into orbit via a commercial carrier rocket, make atmospheric reentry, and land horizontally on a runway.

Once it reaches orbit, it will unfold its solar panels and open its docking shield. The shuttle’s rear will dock with Tiangong, where taikonauts can access the cargo bay and transfer the payload to the space station. According to Fang, “the Hoalong can receive maintenance similar to an aircraft after landing, so it can conduct another mission.” The spacecraft has already completed the design phase and is moving into engineering development. Fang indicated that this phase is well underway and will be followed by the cargo mission phase. “I believe that the public will see it soon,” he said.

Meanwhile, the Qingzhou cargo spacecraft has a cargo volume of up to 27 cubic meters, which is expected to provide logistics flexibility and significantly reduce transportation costs. According to Xinhua, Qingzhou also has an intelligent transportation system capable of supporting crewed and uncrewed in-orbit experiments. The cargo spacecraft is scheduled to be launched by the Lijian-2, a reusable rocket currently under development by CAS Space. This rocket is one of several reusable medium-lift launch vehicles China plans to debut in the coming years.

Lin also noted that “this strategic move will not only slash cargo transportation costs for the space station but also pave the way for new opportunities in the growth of the country’s commercial space industry.” According to market research, China’s commercial space industry is expected to reach a market value of 2.34 trillion yuan ($323.35 billion) by the end of 2024.

Further Reading: Global Times

The post China’s Proposed Cargo Shuttle, the Haolong, Has Entered Development appeared first on Universe Today.

In recent years, astronomers have developed techniques to measure the metal content of stars with extreme accuracy. With that capability, astronomers have examined sibling stars to see how their metallicity differs. Some of these co-natal stars have pronounced differences in their metallicity.

New research shows that stars engulfing rocky planets are responsible.

Co-natal stars are born in the same giant molecular cloud (GMC), though they’re not necessarily in binary relationships with each other. These stars are expected to have very similar metallicities, even though no GMC is totally homogenous and small differences are common in the stars that form together. But when the differences are pronounced, there must be some other explanation.

New research titled “Metal pollution in Sun-like stars from destruction of ultra-short-period planets” suggests that rocky planets are the source of these discrepancies. The authors are Christopher E. O’Connor and Dong Lai from Northwestern University and Cornell University, respectively. The research is on the pre-print server arxiv.org and has been submitted to the AAS journals.

“Detailed studies of chemical composition among co-natal stellar pairs—stars with a common origin—reveal unexpectedly large differential abundances among refractory elements,” the authors write. The authors refer to this as pollution after a similar thing that happens in white dwarfs. The source of this pollution is rocky planets, which are rich in metals.

Ultra-short-period (USP) exoplanets orbit their stars very closely and typically complete an orbit in only a few hours. They have similar compositions to Earth and are seldom more than two Earth radii. Their origins are not clear. They could have formed further out and then migrated closer to their star, or they could be the remains of much larger planets that lost their atmosphere due to stellar irradiation.

This artist’s rendering shows a star stripping away a planet’s atmosphere. Image Credits: NASA/GSFC

USP planets are not very common. Only about 0.5% of Sun-like stars have them. They’re very hot, so their surfaces are melted, and they’re tidally locked to their stars.

Though uncommon, they may form in greater numbers and then be consumed by their stars.

“Short-period exoplanets are potentially vulnerable to tidal disruption and engulfment by their host stars,” the authors write. Research shows that between 3 to 30% of co-natal, main-sequence, Sun-like (FGK) stars have engulfed rocky planets between 1 to 10 Earth masses.

There are many ways this can happen. “Many forms of violent dynamical evolution are possible in planetary systems, each potentially able to inject a planet into the star,” O’Connor and Lai write. However, evidence shows that, at most, about 2% of single FGK stars are polluted by all violent mechanisms combined.

Astronomers have proposed three main scenarios where stars can engulf USP planets.

One is called high-eccentricity (high-e) migration. In this scenario, a proto-USP becomes very close to its star and has a high eccentricity. Because of its proximity to the star and its gravitational draw, the planet rapidly loses its eccentricity and adopts a circular orbit.

Another is low-eccentricity (low-e) migration. In this scenario, the USP migrates towards its star more slowly. Low-e migration occurs in compact systems with three or more planets, which helps moderate its eccentricity.

The well-known TRAPPIST-1 system is an example of a compact, multi-planet system. Image Credit: By NASA/JPL-Caltech – Catalo, Public Domain

The third scenario is obliquity-driven migration. In this scenario, a companion planet to the USP excites the USP’s obliquity and captures it in a secular spin-orbit resonance. The USP rapidly migrates towards its star, but the migration ends when the USP escapes the resonance.

The authors developed a model to predict the number of USPs that form and the time it takes for them to become engulfed. Their model can reproduce both the low observed occurrence of USPs around Sun-like stars and their polluted metallicity. Their results favour the low-e migration scenario where USPs are part of compact, multi-planet systems.

“We find that USP engulfment is a natural consequence of the low-e migration scenario. A connection between USPs and engulfed rocky planets in Sun-like stars, therefore, seems plausible,” they write.

Their results show that USPs become engulfed between 0.1 and 1 gigayear after they form. If this engulfment is the main source of pollution in Sun-like stars, the authors say there’s a correlation between pollution and compact, multi-planet systems. “Some 5–10% of polluted stars should have a transiting planet of mass ? 5M? and period ~ 4–12 days,” they explain. They also predict the reverse: there should be an anti-correlation between USP occurrence and pollution.

The authors point out some caveats regarding their results.

The signatures of metallicity pollution can fade over time. The metals can settle into the star, making the signal disappear. Depending on how effective that is, it could mean our understanding of how many stars are polluted is inaccurate. It could mean more than 30% of Sun-like stars are polluted.

When a star eats a planet, it changes the star’s metallicity, which astronomers call pollution. But the signal from the pollution can fade as the metals sink into the star. Image Credit: International Gemini Observatory/NOIRLab/NSF/AURA/M. Garlick/M. Zamani

The second caveat is that more violent mechanisms could inject planets into their stars. Planet-planet scattering could drive planets into engulfment, especially rocky Super-Earths. However, the authors explain that “We find only ~ 1% of stars can be polluted through the violent destruction of super-Earths, despite their ubiquity as exoplanets.”

Their final caveat concerns Hot Jupiters (HJs). These gas-giant planets orbit very closely to their stars. Astronomers believe that HJs are destroyed by engulfment during their stars’ main sequence lifetime. HJs also have a similar occurrence rate as USPs around Sun-like stars. It’s a fair question to ask if they contribute to the observed metallicity pollution.

This illustration shows a Jupiter-mass exoplanet getting perilously close to its star. If they become engulfed, they may produce a different signature on the star than a rocky planet does. Image Credit: C. Carreau / ESA.

The authors say it’s possible that high-eccentricity migration can drive HJs into stellar engulfment. However, they also point out that there’s good reason to doubt that. “Again, an engulfed HJ may not produce a similar chemical signature to a rocky planet: the masses and bulk metallicities of HJs vary
widely,” they write. All of the hydrogen and helium in HJs could also dilute the extra metals. Additionally, tidal disruption of HJs may not lead directly to engulfment. It’s possible that mass transfer could reduce the HJ down to a super-Earth remnant made of the original core and a residual atmosphere.

According to O’Connor and Lai, more study is needed before we can understand how HJs might contribute to stellar pollution.

Their results also show that a main sequence star can only form one USP during its main sequence, so only one can be engulfed. In a compact system, only the innermost planet can suffer enough tidal decay to become a USP.

In their conclusion, the authors write that stars hosting USPs should have ages and kinematics similar to Milky Way field stars and should rarely show signs of previous planet engulfment. They also conclude that polluted FGK stars should host compact multi-planet systems.

The post Up to a Third of Stars Ate Some of their Planets appeared first on Universe Today.

An exclusive interview with British director David Carson for "Star Trek Generations'" 30th anniversary.

Blue Origin is targeting Friday (Nov. 28) for its NS-28 tourism mission, which will take "Space Gal" Emily Calandrelli and five other people to suborbital space.

A supercomputer simulation of iron and carbon atoms in Earth’s inner core may explain how a molten ball at the centre of our planet froze solid

A supercomputer simulation of iron and carbon atoms in Earth’s inner core may explain how a molten ball at the centre of our planet froze solid

Walmart's Sony camera Black Friday deal price beats Adorama, Amazon and Best Buy by hundreds of dollars.

ABL Space Systems, founded in 2017, will pivot from orbital launch sector to U.S. missile defense programs.

The weird thermodynamics found in time crystals could be harnessed to store energy in a quantum battery-like device

The weird thermodynamics found in time crystals could be harnessed to store energy in a quantum battery-like device

The Pentagon's All-Domain Anomaly Resolution Office will testify before the U.S. Senate on Tuesday (Nov. 19) about its latest report starting at 4:30 p.m. ET (2130 GMT).