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Topic Review
JPL Mars Helicopter Scout
The Mars Helicopter Scout (MHS) is a planned robotic helicopter that will test the technology to scout interesting targets for study on Mars, and help plan the best driving route for future Mars rovers. The small drone helicopter will be deployed in 2021 from the planned Mars 2020 rover. It is expected to fly up to five times during its 30-day test campaign, early in the rover's mission, as it is primarily a technology demonstration. Each flight will take no more than 3 minutes, at altitudes ranging from 3 m to 10 m above the ground, but it could potentially cover a maximum distance of about 600 m (2,000 ft) per flight. It will use autonomous control and communicate with the Mars 2020 rover directly after each landing. If it works as expected, NASA will be able to build on the design for future Mars missions. MiMi Aung is the project lead. Other team members are AeroVironment Inc., NASA Ames Research Center, and NASA Langley Research Center.
  • 396
  • 24 Nov 2022
Topic Review
Soyuz TM-23
Soyuz TM-23 was a Soyuz spaceflight which launched on February 21, 1996, to Mir. The spacecraft launched from Baikonur Cosmodrome, and after two days of flight, Yuri Onufrienko and Yury Usachov docked with Mir and became the 21st resident crew of the Station. On September 2, 1996, after 191 days docked with Mir, the ship undocked with the launch crew and Claudie André-Deshays onboard, before eventually landing 107 km (66 mi) south west of Akmola, Kazakhstan.
  • 389
  • 28 Nov 2022
Topic Review
EnVision (Spacecraft)
EnVision is a proposed orbital mission to Venus that would perform high-resolution radar mapping and atmospheric studies. The mission would help scientists understand the relationships between its geological activity and the atmosphere, and it would investigate why Venus and Earth took such different evolutionary paths. The mission is studied by ESA in collaboration with NASA, with the potential sharing of responsibilities currently under assessment.
  • 379
  • 27 Oct 2022
Topic Review
The Structure and Evolution of Stars
Generally speaking, stars consist of three regimes: a core, an envelope, and an atmosphere from which the light emerges. Depending on the stellar mass and the evolutionary stage, cores and envelopes can be either radiative or convective. These regions define the (dominant) form of energy transport, but their physical definition and the interface between them represent a large source of uncertainty in stellar structure theory. Whilst stellar atmospheres are key messengers of astronomical information, they are also physical laboratories of radiation pressure leading to radiation-driven winds for high-mass stars and chemical mixing and transport phenomena such as radiative levitation in hot low-mass stars, which is where heavy elements with large cross-sections can gain momentum by absorbing photons from outflowing radiation.
  • 379
  • 25 Oct 2023
Topic Review
Circinus
Circinus is a small, faint constellation located in the southern sky. Named after the Latin word for compass, it was first introduced in the 18th century by the French astronomer Nicolas Louis de Lacaille during his observations of the southern hemisphere. Despite its modest size, Circinus harbors several intriguing celestial objects, including a notable planetary nebula and multiple star systems of scientific interest.
  • 379
  • 08 Mar 2024
Topic Review
Pavo
Pavo, Latin for "peacock," is a small but distinct constellation in the southern sky. Representing the majestic bird from ancient mythology, Pavo is notable for its compact arrangement of stars and its proximity to the south celestial pole, making it a prominent feature of the southern hemisphere's night sky.
  • 377
  • 15 Mar 2024
Topic Review
Soyuz TM-21
Soyuz TM-21 was a crewed Soyuz spaceflight to Mir. The mission launched from Baikonur Cosmodrome, atop a Soyuz-U2 carrier rocket, at 06:11:34 UTC on March 14, 1995. The flight marked the first time thirteen humans were flying in space simultaneously, with three aboard the Soyuz, three aboard Mir and seven aboard Space Shuttle Endeavour, flying STS-67. The spacecraft carried expedition EO-18 to the space station. This included the first American astronaut to launch on a Soyuz spacecraft and board Mir, Norman Thagard, for the American Thagard Increment aboard the station, which was the first Increment of the Shuttle-Mir program. The three crew members it launched were relieved by Space Shuttle Atlantis during STS-71, when they were replaced by expedition EO-19. The crew returned to earth aboard Soyuz TM-21 on September 11, 1995.
  • 373
  • 16 Nov 2022
Topic Review
The Evolution of Ryugu
The asteroid 1999 JU3, which would later be named Ryugu, was classified as a Cg-type asteroid in 2001, based on its strong UV absorption feature shortward of 0.55 um and its flat to slightly reddish slope longward of 0.55 um. Cg-type asteroids are part of the C-complex of asteroids, which were suggested to be “primitive” in nature and potentially the parent bodies for carbonaceous chondrites. The linking of carbonaceous chondrites and C-complex asteroids relates to several interpretations concerning features in the near infrared spectra of C-complex asteroids. The features were interpreted as arising from secondary alteration minerals, including goethite, hematite, jarosite and phyllosilicates, that are the products of aqueous alteration and which are found in carbonaceous chondrites.
  • 373
  • 18 Jul 2023
Topic Review
Venus In Situ Atmospheric and Geochemical Explorer
Venus In Situ Atmospheric and Geochemical Explorer (VISAGE) is a proposed Venus lander mission that would perform atmospheric and surface science investigations. The mission was proposed in 2017 to NASA's New Frontiers program to compete for funding and development, but it was not selected.
  • 372
  • 07 Nov 2022
Topic Review
Maintainance of the International Space Station
Since construction started, the International Space Station programme has had to deal with several maintenance issues, unexpected problems and failures. These incidents have affected the assembly timeline, led to periods of reduced capabilities of the station and in some cases could have forced the crew to abandon the space station for safety reasons, had these problems not been resolved.
  • 369
  • 18 Oct 2022
Topic Review
Coma Berenices
Coma Berenices, Latin for "Berenice's Hair," is a constellation in the northern celestial hemisphere. Named after the ancient Egyptian queen Berenice II, it is renowned for its distinctive asterism resembling a flowing mane of hair. Coma Berenices contains several notable celestial objects, including the Coma Cluster of galaxies.
  • 368
  • 08 Mar 2024
Topic Review
Nemesis
Nemesis is a hypothesized companion object orbiting the Sun, motivated by the claim of a terrestrial extinction periodicity. Astronomer Percival Lowell in 1915 thought that some glitches in the orbit of Uranus might be caused by what he dubbed Planet X, and led to the discovery of Pluto in 1930. The existence of the object beyond Pluto may be able to explain the architecture of the Edgeworth–Kuiper Belt and a secular perihelion precession of Saturn. The Nemesis hypothesis has also been used to explain the measurements of the ages of 155 lunar spherules from the Apollo 14 site.
  • 359
  • 14 Jan 2024
Topic Review
SDSS J001820.5-093939.2
SDSS J001820.5–093939.2 or SDSS J0018-0939 for short is a star system approximately 1000 light-years away near the constellation Cetus. SDSS J0018-0939 is a cool main-sequence star. It is the first star found proposed to be a massive second generation star.
  • 358
  • 18 Oct 2022
Topic Review
Water Ice Resources on Shallow Subsurface of Mars
The planet Mars is the most probable among the terrestrial planets in our solar system to support human settlement or colonization in the future. The detection of water ice or liquid water on the shallow subsurface of Mars is a crucial scientific objective for both the Chinese Tianwen-1 and United States Mars 2020 missions, which were launched in 2020. Both missions were equipped with Rover-mounted ground-penetrating radar (GPR) instruments, specifically the RoPeR on the Zhurong rover and the RIMFAX radar on the Perseverance rover. The in situ radar provides unprecedented opportunities to study the distribution of shallow subsurface water ice on Mars with its unique penetrating capability. The presence of water ice on the shallow surface layers of Mars is one of the most significant indicators of habitability on the extraterrestrial planet.
  • 356
  • 27 Mar 2024
Topic Review
Steppe Polecat
The Steppe Polecat, scientifically known as Mustela eversmannii, is a small carnivorous mammal native to the steppes and semi-deserts of Central Asia. With a sleek body and distinctive facial markings, this elusive predator is well-adapted to its arid habitat, where it preys on rodents, birds, and insects. Despite its relatively small size, the Steppe Polecat plays a crucial role in controlling rodent populations and maintaining the balance of its ecosystem.
  • 342
  • 15 Mar 2024
Topic Review
Shallow Geological Structures of CE-4 Landing Site
China has successfully carried out five lunar exploration missions since 2007. These missions indicate that China has successfully implemented a three-step lunar exploration program of “orbiting, landing, and returning”. Among them, the Lunar Penetrating Radar (LPR) carried by the Yutu-2 rover in the Chang’E-4 (CE-4) mission is the only one still operating on the far side of the Moon.
  • 338
  • 31 Oct 2023
Topic Review
Fornax
Fornax, Latin for "furnace," is a small and faint constellation located in the southern celestial hemisphere. Despite its modest size, Fornax is home to several notable deep-sky objects, including the Fornax Cluster of galaxies. French astronomer Nicolas Louis de Lacaille bestowed the name "Fornax" upon this constellation in 1756, and it is now recognized as one of the 88 modern constellations.
  • 333
  • 15 Mar 2024
Topic Review
List of Unnumbered Minor Planets: 2002 A–O
This is a partial list of unnumbered minor planets for principal designations assigned between 1 January 2002 and 31 July 2002 (A–O).
  • 326
  • 29 Nov 2022
Topic Review
Chamaeleon
Chamaeleon, a small and inconspicuous constellation in the southern celestial hemisphere, represents the chameleon, a creature known for its ability to change color and blend into its surroundings. Despite its modest size, Chamaeleon holds significance in astronomy for its proximity to the southern celestial pole and its role in studying star formation and stellar evolution.
  • 325
  • 08 Mar 2024
Topic Review
Northern Light (Spacecraft)
Northern Light was a concept mission for a robotic mission to Mars that would consist of a lander and a rover, being studied by a consortium of Canadian universities, companies and organisations. The primary contractor for the spacecraft was Thoth Technology Inc. The spacecraft would consist of four parts: an apogee kick engine to provide orbital injection for a cruise vehicle that carries the Northern Light lander and the Beaver Rover to a direct rendezvous with Mars using a Hohmann transfer orbit. Atmospheric entry would be achieved by a heat shield, parachute and airbag deployment system. The lander would transfer the rover to the Martian surface. Once deployed on the Martian surface, the lander contacts Earth directly to the 46 m parabolic antenna located at the Algonquin Radio Observatory. The Beaver Rover was proposed to have a maximum range of 1000 metres (0.62 mile) from the landing site. It would have operated under battery, utilizing tools and sensors to investigate surface rocks that may contain the presence of photosynthetic life.
  • 321
  • 03 Nov 2022
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