Pluto's Dark Side Revealed | Planet Explorers | BBC Earth Lab - planetary science

About the Green Comet C/2022 E3 (ZTF)

The Green Comet is green because its head contains diatomic carbon.This is a form of carbon molecule with two atoms of carbon each.When the comet draws near the Sun,the diatomic carbon gives off a green glow because of a chemical reaction with the solar wind.* The Green Comet is believed to have originated in the Oort Cloud.The Oort Cloud is a theoretical construct referring to the most distant area of the solar system.It is thought to contain icy celestial bodies such as comets.The Oort Cloud is far beyond Pluto.It is so far away,it is believed to be one quarter to one half the distance to the nearest star,Proxima Centauri.No spacecraft has ever visited the Oort Cloud.Indeed,Voyager I will need another 300 years to reach it.* The Green Comet will not return for 50,000 years.When it was last visible from Earth,Neanderthals co-existed with Cro-Magnon,or modern humans.

Exploring Dwarf Planet Ceres:NASA,Spacecraft and Industry

On Friday 6 March,NASA's Dawn spacecraft became the first spacecraft in history to orbit a dwarf planet.At 07:39 ET,Dawn began orbiting dwarf planet Ceres,which is in the Main Asteroid Belt,between Mars and Jupiter.Dawn called home to Mission Control at the Jet Propulsion Laboratory in Pasadena,California to say it was in good health and its ion propulsion engine,one of the first to be tested,was thrusting it into orbit.Principal Investigator Chris Russell of the University of California Los Angeles expressed his exhilaration at hearing the news.Also partnering in the mission are the German Aerospace Center;the Max Planck Institute for Solar System Research;the Italian Space Agency;and the Italian National Astrophysical Institute.
Formerly classified as an asteroid,Ceres was elevated to dwarf planet status in 2006;while Pluto was demoted from planet to dwarf planet.The average diameter of Ceres is 590 miles.An icy world,it has craters and bright spots on its surface that are not well understood.Dawn will emerge from Ceres' dark side in April and spiral down for ever-closer photos and measurements.When the mission ends in 2016,Dawn will continue to orbit Ceres,which is 3.1 billion miles from Earth.Dawn first explored the giant asteroid Vesta from 2011-13 before going on to Ceres.*
Orbital ATK,based in Dulles,Virginia,designed and built the Dawn spacecraft.Dawn's ion propulsion system,a deep space engine system,is the next step in propulsion technology.The system is called the NASA Evolutionary Xenon Thruster,or NEXT.Dawn's engines ionise,or charge,Xenon fuel atoms and accelerate these ions out of the back using high voltage.NASA says the ion propulsion system's efficient use of fuel and electrical power enable modern spacecraft to travel farther,faster and cheaper.The systems are use for stationkeeping on communications satellites and for main propulsion on deep space probes.*
Orbital Sciences and Alliant Techsystems completed their merger into Orbital ATK on 10 February.The company's more than 12,000 employees are spread across three divisions:
1.Flight Systems Group in Chandler,Arizona-4500 employees.
2.Defense Systems Group in Baltimore,Maryland-4900 employees.
3.Space Systems Group in Dulles,Virginia-2700 employees.
Besides space probes and other satellites,the company produces the Antares rocket and Cygnus cargo spacecraft under contract to NASA for the International Space Station.Its other products include antennae and radomes;munitions and weapons;as well as rocket engines,missile components and defence electronics.*
Orbital ATK Inc (ATK)