PLUTO'S MOONS, NIX (134340 PII) & HYDRA (134340 PIII)

Last night in Mallorca and last chance to see a much clearer sky than in Barcelona. The Grandma has taken her telescope and has been observing a part of this majestic universe just on the same day that twenty years ago Pluto's newly discovered moons were officially named Nix and Hydra. Tomorrow it will be time to say goodbye to friends and family and return to Barcelona where three new formations await her during these months of June and July. In fact, it is not goodbye but a so far, because Mallorca, like Napoli, Montpelhièr, Lyon or Bergen is home for The Grandma.

Nix, formal designation (134340) Pluto II, is a natural satellite of Pluto, with a diameter of 49.8 km across its longest dimension. It was discovered along with Pluto's outermost moon Hydra on 15 May 2005 by astronomers using the Hubble Space Telescope, and was named after Nyx, the Greek goddess of the night.  

Nix is the third moon of Pluto by distance, orbiting between the moons Styx and Kerberos.

Nix was imaged along with Pluto and its other moons by the New Horizons spacecraft as it flew by the Pluto system in July 2015. These images reveal a large reddish area on Nix that is likely an impact crater.

Nix was independently discovered by Max Mutchler and Andrew Steffl, members of the Pluto Companion Search Team, using the Hubble Space Telescope. The New Horizons team had suspected that Pluto and its moon Charon might be accompanied by other moons, hence they used Hubble to search for faint moons around Pluto in 2005. Since Nix's brightness is about 5,000 times fainter than Pluto, long exposure images were taken in order to find it.

The discovery images were taken on 15 May 2005 and 18 May 2005. The discoveries were announced on 31 October 2005, after confirmation by precovering archival Hubble images of Pluto from 2002. The two newly announced moons of Pluto were subsequently provisionally designated S/2005 P 1 for Hydra and S/2005 P 2 for Nix. The moons were informally referred to as "P1" and "P2", respectively by the discovery team.

The name Nix was approved by the International Astronomical Union (IAU) and was announced on 21 June 2006 along with the naming of Hydra in the IAU Circular 8723. 

Nix was named after Nyx, the Greek goddess of darkness and night and mother of Charon, the ferryman of Hades in Greek mythology. The original proposal for the naming of Nix was to use the classical spelling Nyx, but to avoid confusion with the asteroid 3908 Nyx, the spelling was changed to Nix, the Coptic spelling of the name. The adjectival form of the name is Nictian (cf. Russian Никта Nikta).

More information: NASA

Hydra, formal designation (134340) Pluto III, is a natural satellite of Pluto, with a diameter of approximately 51 km across its longest dimension. It is the second-largest moon of Pluto, being slightly larger than Nix. Hydra was discovered along with Nix by astronomers using the Hubble Space Telescope on 15 May 2005, and was named after the Hydra, the nine-headed underworld serpent in Greek mythology. By distance, Hydra is the fifth and outermost moon of Pluto, orbiting beyond Pluto's fourth moon Kerberos.

Hydra has a highly reflective surface caused by the presence of water ice, similar to other Plutonian moons. Hydra's reflectivity is intermediate, in between those of Pluto and Charon. The New Horizons spacecraft imaged Pluto and its moons in July 2015 and returned multiple images of Hydra.

Members of the New Horizons team suspected that Pluto and Charon might be accompanied by other small, distant moons, weakly bound to the Pluto system. They used the Hubble Space Telescope to test this hypothesis. This led to the discovery of Nix and Hydra -both surprisingly close to Pluto/Charon- and that no significant moons existed in Pluto's extended sphere of influence.

The discovery images were taken on 15 May 2005 and 18 May 2005. Hydra and Nix were independently discovered by Max J. Mutchler on 15 June 2005 and by Andrew J. Steffl on 15 August 2005. The discoveries were announced on 31 October 2005, after confirmation by precovering archival Hubble images of Pluto from 2002. The two newly discovered moons were subsequently provisionally designated S/2005 P 1 for Hydra and S/2005 P 2 for Nix. The moons were informally referred to as "P1" and "P2" respectively, by the discovery team.

The name Hydra was approved on 21 June 2006 by the International Astronomical Union (IAU) and was announced along with the naming of Nix in the IAU Circular 8723. 

Hydra was named after the Lernaean Hydra, a multi-headed serpent that battled Heracles/Hercules in Greek and Roman mythology. Particularly, the nine heads of Hydra subtly references Pluto's former ninth planetary status. The two newly named moons were intentionally named that the order of their initials N and H honors the New Horizons mission to Pluto, similarly to how the first two letters of Pluto's name honors Percival Lowell.

The names of features on the bodies in the Pluto system are related to mythology and the literature and history of exploration. In particular, the names of features on Hydra must be related to legendary serpents and dragons from literature, mythology, and history.

More information: NASA

 I tend to think of Pluto and its moons 
as presents sitting under a Christmas tree. 
They're wrapped, and from Earth 
all we can do is look at the boxes
 to see whether they're light or heavy, 
to see if something maybe jiggles a bit inside. 
We're seeing intriguing things, 
but we really don't know what's in there.

Alan Stern

NEPTUNE IS DISCOVERED AT THE BERLIN OBSERVATORY

Today, The Grandma has received the wonderful visit of Joseph de Ca'th Lon, one of her best friends. 

 

Joseph loves Astronomy and they have been talking about Neptune, the planet that was discovered on a day like today in 1846.

Neptune is the eighth planet from the Sun and the farthest known solar planet. In the Solar System, it is the fourth-largest planet by diameter, the third-most-massive planet, and the densest giant planet. It is 17 times the mass of Earth, and slightly more massive than its near-twin Uranus. 

Neptune is denser and physically smaller than Uranus because its greater mass causes more gravitational compression of its atmosphere. It is referred to as one of the solar system's two ice giant planets, the other one being Uranus.

Being composed primarily of gases and liquids, it has no well-defined solid surface. The planet orbits the Sun once every 164.8 years at an average distance of 30.1 AU (4.5 billion km; 2.8 billion mi). It is named after the Roman god of the sea and has the astronomical symbol ♆, representing Neptune's trident.

Neptune is not visible to the unaided eye and is the only planet in the Solar System found by mathematical prediction rather than by empirical observation. Unexpected changes in the orbit of Uranus led Alexis Bouvard to hypothesise that its orbit was subject to gravitational perturbation by an unknown planet. After Bouvard's death, the position of Neptune was predicted from his observations, independently, by John Couch Adams and Urbain Le Verrier.

More information: NASA

Neptune was subsequently observed with a telescope on 23 September 1846 by Johann Galle within a degree of the position predicted by Le Verrier. Its largest moon, Triton, was discovered shortly thereafter, though none of the planet's remaining 13 known moons were located telescopically until the 20th century.

The planet's distance from Earth gives it a very small apparent size, making it challenging to study with Earth-based telescopes.  

Neptune was visited by Voyager 2, when it flew by the planet on 25 August 1989; Voyager 2 remains the only spacecraft to have visited Neptune. The advent of the Hubble Space Telescope and large ground-based telescopes with adaptive optics has recently allowed for additional detailed observations from afar.

Like Jupiter and Saturn, Neptune's atmosphere is composed primarily of hydrogen and helium, along with traces of hydrocarbons and possibly nitrogen, though it contains a higher proportion of ices such as water, ammonia and methane. However, similar to Uranus, its interior is primarily composed of ices and rock; Uranus and Neptune are normally considered ice giants to emphasise this distinction.

Along with Rayleigh scattering, traces of methane in the outermost regions in part account for the planet's blue appearance. Newest data from the Gemini observatory shows the blue color is more saturated than the one present on Uranus due to thinner haze of Neptune's more active atmosphere.

In contrast to the hazy, relatively featureless atmosphere of Uranus, Neptune's atmosphere has active and visible weather patterns. For example, at the time of the Voyager 2 flyby in 1989, the planet's southern hemisphere had a Great Dark Spot comparable to the Great Red Spot on Jupiter. More recently, in 2018, a newer main dark spot and smaller dark spot were identified and studied.

In addition, these weather patterns are driven by the strongest sustained winds of any planet in the Solar System, with recorded wind speeds as high as 2,100 km/h. Because of its great distance from the Sun, Neptune's outer atmosphere is one of the coldest places in the Solar System, with temperatures at its cloud tops approaching −218 °C. Temperatures at the planet's centre are approximately 5,100 °C.

Neptune has a faint and fragmented ring system (labelled "arcs"), which was discovered in 1984, then later confirmed by Voyager 2.

More information: NASA

 What I want to look at with Webb is
what we call ice giants in our solar system
-the planets Neptune and Uranus.

Heidi Hammel

SPACE SHUTTLE DISCOVERY & HUBBLE SPACE TELESCOPE

Today, The Grandma has received the wonderful visit of one of her closest friends, Joseph de Ca'th Lon.

 

Joseph loves Astronomy and Science and they have been talking about the Space Shuttle Discovery that was launched on a mission to service the Hubble Space Telescope on a day like today in 1997.

 

Space Shuttle Discovery, Orbiter Vehicle Designation: OV-103, is one of the orbiters from NASA's Space Shuttle program and the third of five fully operational orbiters to be built.

Its first mission, STS-41-D, flew from August 30 to September 5, 1984. Over 27 years of service it launched and landed 39 times, aggregating more spaceflights than any other spacecraft to date.

The Space Shuttle launch vehicle has three main components: the Space Shuttle orbiter, a single-use central fuel tank, and two reusable solid rocket boosters. Nearly 25,000 heat-resistant tiles cover the orbiter to protect it from high temperatures on re-entry.

Discovery became the third operational orbiter to enter service, preceded by Columbia and Challenger. It embarked on its final mission, STS-133, on February 24, 2011, and touched down for the last time at Kennedy Space Center on March 9, having spent a cumulative total of nearly a full year in space. Discovery performed both research and International Space Station (ISS) assembly missions, and also carried the Hubble Space Telescope into orbit.

Discovery was the first operational shuttle to be retired, followed by Endeavour and then Atlantis. The shuttle is now on display at the Steven F. Udvar-Hazy Center of the Smithsonian National Air and Space Museum.

The name Discovery was chosen to carry on a tradition based on ships of exploration, primarily HMS Discovery, one of the ships commanded by Captain James Cook during his third and final major voyage from 1776 to 1779, and Henry Hudson's Discovery, which was used in 1610–1611 to explore Hudson Bay and search for a Northwest Passage. Other ships bearing the name have included HMS Discovery of the 1875-1876 British Arctic Expedition to the North Pole and RRS Discovery, which led the 1901-1904 Discovery Expedition to Antarctica.

More information: NASA

Discovery launched the Hubble Space Telescope and conducted the second and third Hubble service missions. It also launched the Ulysses probe and three TDRS satellites. Twice Discovery was chosen as the Return To Flight Orbiter, first in 1988 after the loss of Challenger in 1986, and then again for the twin Return To Flight missions in July 2005 and July 2006 after the Columbia disaster in 2003.

Project Mercury astronaut John Glenn, who was 77 at the time, flew with Discovery on STS-95 in 1998, making him the oldest person to go into space at that time in history.

Had plans to launch United States Department of Defense payloads from Vandenberg Air Force Base gone ahead, Discovery would have become the dedicated US Air Force shuttle. Its first West Coast mission, STS-62-A, was scheduled for 1986, but canceled in the aftermath of the Challenger disaster.

Discovery was retired after completing its final mission, STS-133 on March 9, 2011. The spacecraft is now on display in Virginia at the Steven F. Udvar-Hazy Center, an annex of the Smithsonian Institution's National Air and Space Museum.

The Hubble Space Telescope, often referred to as HST or Hubble, is a space telescope that was launched into low Earth orbit in 1990 and remains in operation.

It was not the first space telescope, but it is one of the largest and most versatile, renowned both as a vital research tool and as a public relations boon for astronomy. 

The Hubble telescope is named after astronomer Edwin Hubble and is one of NASA's Great Observatories, along with the Compton Gamma Ray Observatory (1991-2000), the Chandra X-ray Observatory (1999-present), and the Spitzer Space Telescope (2003-2020).

The Space Telescope Science Institute (STScI) selects Hubble's targets and processes the resulting data, while the Goddard Space Flight Center (GSFC) controls the spacecraft.

Hubble features a 2.4 m mirror, and its five main instruments observe in the ultraviolet, visible, and near-infrared regions of the electromagnetic spectrum. 

Hubble's orbit outside the distortion of atmosphere of Earth allows it to capture extremely high-resolution images with substantially lower background light than ground-based telescopes.

More information: Smithsonian National Air and Space Museum

It has recorded some of the most detailed visible light images, allowing a deep view into space. Many Hubble observations have led to breakthroughs in astrophysics, such as determining the rate of expansion of the universe.

Space telescopes were proposed as early as 1923. Hubble was funded in the 1970s and built by the United States space agency NASA with contributions from the European Space Agency.

Its intended launch was 1983, but the project was beset by technical delays, budget problems, and the 1986 Challenger disaster. Hubble was finally launched in 1990, but its main mirror had been ground incorrectly, resulting in spherical aberration that compromised the telescope's capabilities. The optics were corrected to their intended quality by a servicing mission in 1993.

Hubble is the only telescope designed to be maintained in space by astronauts. Five Space Shuttle missions have repaired, upgraded, and replaced systems on the telescope, including all five of the main instruments.

The fifth mission was initially canceled on safety grounds following the Columbia disaster (2003), but after NASA administrator Michael D. Griffin approved it, it was completed in 2009.

The telescope completed 30 years of operation in April 2020 and is predicted to last until 2030–2040. One successor to the Hubble telescope is the James Webb Space Telescope (JWST), which was launched on December 25, 2021.

More information: Space

 All the NASA footage is in the public domain,
and it's so beautiful; it's really stunning.

Stephanie Savage