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Topic Review
(469219) 2016 HO3
(469219) 2016 HO3 is a micro-asteroid, fast rotator and near-Earth object of the Apollo group, approximately 41 meters in diameter. It is currently the smallest, closest, and most stable (known) quasi-satellite of Earth. The asteroid was discovered by Pan-STARRS at Haleakala Observatory on 27 April 2016.
  • 1.2K
  • 03 Nov 2022
Topic Review
Venus (Planet)
Venus is the second-closest planet to the Sun, orbiting it every 224.7 Earth days. After Earth's Moon, it is the brightest object in the night sky, reaching an apparent magnitude of −4.6. As an inferior planet from Earth it never appears to venture far from the Sun, and its elongation reaches a maximum of 47.8°. Venus reaches its maximum brightness shortly before sunrise or shortly after sunset, and is often referred to as the Morning Star or as the Evening Star. A terrestrial planet, it is sometimes called Earth's "sister planet", as the two are similar in size and bulk composition. The planet is covered with an opaque layer of highly reflective clouds and its surface cannot be seen from space in visible light, making it a subject of great speculation until some of its secrets were revealed by planetary science in the 20th century. Venus has the densest atmosphere of the terrestrial planets, consisting mostly of carbon dioxide, and the atmospheric pressure at the planet's surface is 90 times that of the Earth. Venus' surface has been mapped in detail only in the last 20 years. It shows evidence of extensive volcanism, and some of its volcanoes may still be active today. In contrast to the constant crustal movement seen on Earth, Venus is thought to undergo periodic episodes of plate tectonics, in which the crust is subducted rapidly within a few million years separated by stable periods of a few hundred million years. The planet is named after Venus, the Roman goddess of love, and most of its surface features are named after famous and mythological women. The adjective Venusian is commonly used for items related to Venus, though the Latin adjective is the rarely used Venereal; the now-archaic Cytherean is still occasionally encountered.
  • 1.2K
  • 01 Nov 2022
Topic Review
Grahan Mala
Grahan Mala is an astronomical treatise on the calculation of the dates and timings for the lunar and solar eclipses written by the Indian Astronomer Hemangad Thakur in the 16th century AD.
  • 1.2K
  • 15 Dec 2023
Topic Review
2020 XL5
2020 XL5 is a near-Earth asteroid and Earth trojan discovered by the Pan-STARRS 1 survey at Haleakala Observatory, Hawaii on 12 December 2020. It oscillates around the Sun–Earth L4 Lagrangian point (leading 60°), one of the dynamically stable locations where the combined gravitational force acts through the Sun's and Earth's barycenter. Analysis of 2020 XL5's trojan orbit stability suggests it will remain around Earth's L4 point for at least four thousand years until gravitational perturbations from repeated close encounters with Venus destabilize its trojan configuration. With a diameter about 1.2 km (0.75 mi), 2020 XL5 is the second Earth trojan discovered and is the largest of its kind known, after 2010 TK7.
  • 1.2K
  • 18 Oct 2022
Topic Review
White Hole
White holes are regions of space-time that although matter may come out, no matter is able to enter; or in other words, they have gravitational features opposite to those of black holes. White holes exist in the solutions to Einstein's general theory of relativity and the maximal extension of the Schwarzschild metric. The term "white hole" was coined by Soviet cosmologist Igor Novikov in 1965 after his theorization on the existence.
  • 1.1K
  • 15 Oct 2023
Topic Review
Advanced Technology Large-Aperture Space Telescope
The Advanced Technology Large-Aperture Space Telescope (ATLAST) is an 8– to 16.8–meter UV-optical-NIR space telescope proposed by the Space Telescope Science Institute (STScI), the science operations center for the Hubble Space Telescope (HST). If launched, ATLAST would be a replacement and successor for the HST, with the ability to obtain spectroscopic and imaging observations of astronomical objects in the ultraviolet, optical, and infrared wavelengths, but with substantially better resolution than either HST or the planned James Webb Space Telescope (JWST). Like JWST, ATLAST would be launched to the Sun-Earth L2 Lagrange point. ATLAST is envisioned as a flagship mission of the 2025–2035 period, designed to determine whether there is life elsewhere in the galaxy. It would attempt to accomplish this by searching for "biosignatures" (such as molecular oxygen, ozone, water, and methane) in the spectra of terrestrial exoplanets. The backronym that the project currently uses, 'ATLAST', is in fact a pun. It refers to the time taken to decide on a true, visible-light, successor for the Hubble Space Telescope. However, it is expected that, as the project progresses, a new name would be chosen for the mission.
  • 1.1K
  • 25 Oct 2022
Topic Review
Perseus
Perseus, a prominent constellation in the northern celestial hemisphere, is named after the legendary Greek hero known for slaying the monstrous Gorgon Medusa. Located near the celestial equator, Perseus is recognizable for its distinctive "W" shape formed by its brightest stars and is rich in fascinating deep-sky objects.
  • 1.1K
  • 15 Mar 2024
Topic Review
Large Synoptic Survey Telescope
The Large Synoptic Survey Telescope (LSST) is a wide-field survey reflecting telescope with an 8.4-meter primary mirror, currently under construction, that will photograph the entire available sky every few nights. The word synoptic is derived from the Greek words σύν (syn "together") and ὄψις (opsis "view"), and describes observations that give a broad view of a subject at a particular time. The telescope uses a novel 3-mirror design, a variant of three-mirror anastigmat, which allows a compact telescope to deliver sharp images over a very wide 3.5-degree diameter field of view. Images will be recorded by a 3.2-gigapixel CCD imaging camera, the largest digital camera ever constructed. The telescope is located on the El Peñón peak of Cerro Pachón, a 2,682-meter-high mountain in Coquimbo Region, in northern Chile , alongside the existing Gemini South and Southern Astrophysical Research Telescopes. The LSST Base Facility is located about 100 kilometres (62 mi) away by road, in the town of La Serena. The LSST was proposed in 2001, and construction of the mirror began (with private funds) in 2007. LSST then became the top-ranked large ground-based project in the 2010 Astrophysics Decadal Survey, and the project officially began construction 1 August 2014 when the National Science Foundation (NSF) authorized the FY2014 portion ($27.5 million) of its construction budget. The ceremonial laying of the first stone was performed on 14 April 2015. Site construction began on April 14, 2015, with engineering first light anticipated in 2019, science first light in 2021, and full operations for a ten-year survey commencing in January 2022. LSST, unlike almost all previous large astronomical observatories, has committed to making all data public as soon as it is taken. In their words "By providing immediate public access to all the data it obtains, it will provide everyone, the professional and the “just curious” alike, a deep and frequent window on the entire sky."
  • 1.1K
  • 10 Nov 2022
Topic Review
Soyuz 11
Soyuz 11 (Russian: Союз 11, lit. 'Union 11') was the only crewed mission to board the world's first space station, Salyut 1 (Soyuz 10 had soft-docked, but had not been able to enter due to latching problems). The crew, Georgy Dobrovolsky, Vladislav Volkov, and Viktor Patsayev, arrived at the space station on 7 June 1971, and departed on 29 June 1971. The mission ended in disaster when the crew capsule depressurised during preparations for re-entry, killing the three-man crew. The three crew members of Soyuz 11 are the only humans to have died in space.
  • 1.1K
  • 09 Oct 2022
Topic Review
Brite-Constellation
BRITE-Constellation is devoted to high-precision optical photometric monitoring of bright stars, distributed all over the Milky Way, in red and/or blue passbands. Photometry from space avoids the turbulent and absorbing terrestrial atmosphere and allows for very long and continuous observing runs with high time resolution and thus provides the data necessary for understanding various processes inside stars (e.g., asteroseismology) and in their immediate environment. 
  • 1.1K
  • 15 Jul 2021
Biography
Fred Hoyle
Sir Fred Hoyle FRS (24 June 1915 – 20 August 2001)[1] was an English astronomer who formulated the theory of stellar nucleosynthesis. He also held controversial stances on other scientific matters—in particular his rejection of the "Big Bang" theory, a term coined by him on BBC radio, and his promotion of panspermia as the origin of life on Earth.[2][3][4] He also wrote science fiction nove
  • 1.1K
  • 17 Nov 2022
Biography
Albert Einstein
Albert Einstein, born on March 14, 1879, in Ulm, Germany, is widely regarded as one of the most brilliant scientists in human history. His groundbreaking contributions to physics revolutionized our understanding of the universe and earned him worldwide acclaim. Einstein's life and work remain a source of inspiration and fascination, making him an iconic figure in the realm of science and beyond
  • 1.1K
  • 21 Feb 2024
Topic Review
Plutoid
A plutoid or ice dwarf is a trans-Neptunian dwarf planet, i.e. a body orbiting beyond Neptune that is massive enough to be rounded in shape. The term plutoid was adopted by the International Astronomical Union (IAU) working group Committee on Small Bodies Nomenclature, but was rejected by the IAU working group Planetary System Nomenclature. The term plutoid is not widely used by astronomers, though ice dwarf is not uncommon. There are thought to be thousands of plutoids in the Solar System, although only four have been formally designated as such by the IAU. The IAU developed this category of astronomical objects as a consequence of its 2006 resolution defining the word "planet". The IAU's formal definition of "plutoid", announced 11 June 2008, is: In light of the difficulty of remotely ascertaining hydrostasis, the IAU only formally confers "dwarf planet" (and by extension, "plutoid") status to those bodies whose minimum estimated size is substantially greater than what is generally thought necessary to guarantee hydrostatic equilibrium. (As of 2009), Pluto, Eris, Haumea, and Makemake are the only objects officially recognized as plutoids, while upwards of seventy more bodies that currently lack formal recognition are thought likely to meet the definition, and can expect formal recognition at some time in the future. Alan Stern of the Southwest Research Institute believes the outer planets show signs of collisions with plutoids 1,000 to 2,000 kilometers in diameter: Uranus could have been tipped off its axis by a plutoid, and Triton, the largest moon of Neptune, is probably a captured plutoid from the Kuiper belt.
  • 1.1K
  • 21 Nov 2022
Topic Review
Orion
Orion, one of the most recognizable constellations in the night sky, is steeped in mythology and astronomical significance. Named after the legendary hunter from Greek mythology, Orion is adorned with bright stars, including the famous Orion's Belt, and hosts a plethora of celestial wonders, such as the Orion Nebula, making it a favorite among stargazers.
  • 1.1K
  • 15 Mar 2024
Topic Review
Centaur (Minor Planet)
Centaurs are small solar system bodies with a semi-major axis between those of the outer planets. They generally have unstable orbits because they cross or have crossed the orbits of one or more of the giant planets; almost all their orbits have dynamic lifetimes of only a few million years, but there is one centaur, (514107) 2015 BZ509, which may be in a stable (though retrograde) orbit. Centaurs typically behave with characteristics of both asteroids and comets. They are named after the mythological centaurs that were a mixture of horse and human. It has been estimated that there are around 44,000 centaurs in the Solar System with diameters larger than 1 kilometer. The first centaur to be discovered, under the definition of the Jet Propulsion Laboratory and the one used here, was 944 Hidalgo in 1920. However, they were not recognized as a distinct population until the discovery of 2060 Chiron in 1977. The largest confirmed centaur is 10199 Chariklo, which at 260 kilometers in diameter is as big as a mid-sized main-belt asteroid, and is known to have a system of rings. It was discovered in 1997. However, the lost centaur 1995 SN55 may be somewhat larger. No centaur has been photographed up close, although there is evidence that Saturn's moon Phoebe, imaged by the Cassini probe in 2004, may be a captured centaur that originated in the Kuiper belt. In addition, the Hubble Space Telescope has gleaned some information about the surface features of 8405 Asbolus. (As of 2008), three centaurs have been found to display comet-like comas: 2060 Chiron, 60558 Echeclus, and 166P/NEAT. Chiron and Echeclus are therefore classified as both asteroids and comets. Other centaurs, such as 52872 Okyrhoe, are suspected of having shown comas. Any centaur that is perturbed close enough to the Sun is expected to become a comet.
  • 1.1K
  • 25 Nov 2022
Topic Review
Cosmic-ray Sources - Black Holes
Cosmic rays were discovered over one hundred years ago but there are still unsolved problems. One of the hot problems is the origin of cosmic rays of the highest energies. Sources are still unclear and it is neither clear how particles gain ultra-high energies. Possible sources of cosmic rays at the highest energies are supermassive black holes. From this perspective we discuss in a popular form some recent developments in cosmic ray studies along with author’s recent results.The paper also offers materials for further reading.
  • 1.0K
  • 21 Jan 2021
Topic Review
Orion Service Module
The Orion service module is the service module component of the Orion spacecraft, serving as its primary power and propulsion component until it is discarded at the end of each mission. In January 2013, NASA announced that the European Space Agency (ESA) will contribute the service module for Artemis 1, replacing the previous design. Based on ESA's Automated Transfer Vehicle (ATV), the new design is also known as the European service module (ESM). The service module supports the crew module from launch through separation prior to reentry. It provides in-space propulsion capability for orbital transfer, attitude control, and high altitude ascent aborts. It provides the water and oxygen needed for a habitable environment, generates and stores electrical power, and maintains the temperature of the vehicle's systems and components. This module can also transport unpressurized cargo and scientific payloads.
  • 1.0K
  • 28 Nov 2022
Topic Review
PSR B1620-26 B
PSR B1620-26 b is an extrasolar planet located approximately 12,400 light-years away from Earth in the constellation of Scorpius. It bears the unofficial nicknames "Methuselah" and "the Genesis planet" due to its extreme age and a few popular sources refer to this object as "PSR B1620-26 c" (see below for discussion). The planet is in a circumbinary orbit around the two stars of PSR B1620-26 (which are a pulsar (PSR B1620-26 A) and a white dwarf (WD B1620-26)) and is the first circumbinary planet ever confirmed. It is also the first planet found in a globular cluster. The planet is one of the oldest known extrasolar planets, believed to be about 12.7 billion years old.
  • 1.0K
  • 28 Nov 2022
Topic Review
Luch (Satellite)
The Luch (Russian: Луч; lit. Ray) Satellite Data Relay Network (SDRN), also referred to as Altair and Gelios, is a series of geosynchronous Russian relay satellites, used to transmit live TV images, communications and other telemetry from the Soviet/Russian space station Mir, the Russian Orbital Segment (ROS) of the International Space Station and other orbital spacecraft to the Earth, in a manner similar to that of the US Tracking and Data Relay Satellite System.
  • 986
  • 21 Nov 2022
Topic Review
The TACTIC Telescope
The TACTIC (TeV Atmospheric Cherenkov Telescope with Imaging Camera) is a ground-based gamma-ray telescope in India. The telescope was set up at Mount Abu (24.6∘ N, 72.7∘ E, 1300 m above sea level)  in 1997. The operating principle of TACTIC is based on the imaging atmospheric Cherenkov technique for indirect observation of the gamma-ray sky. Since its first light in 1997, the TACTIC telescope has been employed to explore the Universe at TeV energies and several outstanding results are derived from the TACTIC data.  
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  • 28 Apr 2021
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