2.1l Space probes to gain data - Home - GCSE Astronomy ... Space...The most famous flybys were the Pioneer and Voyager missions which set out from Earth in the 1970s. These space

Instruments for magnetic field, solar radiation, temperature, seismology, chemical analysis, atmospheric pressure, as well as sensors in all regions of the electromagnetic spectrum are some of the many pieces of scientific equipment that are loaded on to space probes. Cameras are a vital part of the apparatus, but even sound recording equipment has been put on Mars. The aim is always to keep the weight to a minimum to reduce the payload size at launch. Every conceivable piece of scientific apparatus to collect data can be part of a space probe, with a variety of methods of use.

Flyby – this is where the space probe is targeted on a route, often using the gravitational pull of the planet to accelerate the probe, to take it past as many objects with as close an approach as possible. The most famous flybys were the Pioneer and Voyager missions which set out from Earth in the 1970s. These space probes brought us the first images and detailed observations of the outer planets, as well as information en route to leaving the Solar System.

VOYAGER'S LEGACY

! Voyager 1 is now the most distant human-made object in space

! Study of the region in space where the Sun's influence ends and interstellar space begins

! Discovered Jupiter’s rings

! Found volcanic activity on Jupiter’s moon Io

! Confirmed rings around Uranus and Neptune

! Detailed study of Saturn’s rings and the Red Spot of Jupiter

! Discovery of Neptune’s Great Dark Spot

2.1l describe how astronomers use space probes to gain data on the characteristics of planets and other bodies in the Solar System

Picture credits : NASA-History Office/ JPL-Caltech

JUPITER’S RINGS + NEPTUNE’S GREAT DARK SPOT

Another impressive flyby was the Giotto space probe that took the first close up image of the nucleus of Halley’s comet in 1986. The accuracy in targeting such a fast moving object was an incredible achievement.

Picture credit : ESA - Courtesy of MPAe, Lindau

Giotto showed Halley’s comet was 16 km long and mainly made of ice with dust. The spacecraft encountered Halley’s comet on 13th March 1986.

The New Horizons mission to Pluto and the Kuiper Belt is a current long term Mission. This gained incredible images of the dwarf planet Pluto and its 5 moons in the time of the flyby on 14th July 2015. New Horizons flew 12,500 km above the surface of Pluto at closest approach. The mission has helped us understand so much more about what used to be the 9th planet of the Solar System will be especially important in understanding more about the area of the Solar System beyond the planets, the Kuiper Belt - where short period comets are found. Objects formed right at the birth of our Solar System have been preserved in the intense cold and analysis of objects will help us learn more about how our Solar System was formed 4.5 billion years ago. The trajectory of the spacecraft has been adjusted so that there will be a flyby of Kuiper Belt object 2014 MU69 on 1st January 2019 (43.4AU from the Sun). The Mission clock and other Mission details can be viewed with the link:-

Web credit : NASA/Johns Hopkins University

New Horizons Missionhttp://pluto.jhuapl.edu/

Sputnik Planum

Pluto surface showing the vast Sputnik Planum region

Picture credits : NASA/Johns Hopkins University Applied Physics Laboratory/Southwest Research Institute

Pluto’s largest moon - Charon

Orbit – this is where the space probe reaches a particular object and remains close by over a lengthy period of time. The orbit around the object allows most of the surface to be studied, usually in great detail. On the journey to the object, astronomers may use flyby opportunities to gain new data on a previously visited part of the Solar System. Current missions include the Messenger probe orbiting Mercury and the Dawn mission to orbit the asteroid Vesta and the dwarf planet Ceres. Previous successful missions have been:-

GALILEO 1989 : SURVEY OF JUPITER AND ITS MOONS

Galileo was a spacecraft sent to study Jupiter's atmosphere and cloud patterns (including a study of the Giant Red Spot), the Galilean moons and the magnetic environment around Jupiter. Launched in 1989, the Galileo spacecraft arrived at Jupiter on 7th December 1995. On the same day, Galileo's atmospheric probe plunged into the atmosphere of Jupiter and relayed back information on the structure and composition of Jupiter’s atmosphere. The spacecraft's orbiter then carried on the study of Jupiter and its moons.

GALILEO'S LEGACY ! Photographed Comet Shoemaker-Levy 9 hitting Jupiter in 1994! Spectacular findings about

Jupiter and its moons

Images of giant volcanoes on the moon Io

Picture credits : NASA/JPL-Caltech

! Data on the icy worlds of Ganymede, Callisto and Europa ! Evidence of salty oceans under the icy surface of Europa! First spacecraft to flyby an asteroid (Gaspra) and the first to discover a moon of an asteroid

In order that the aging spacecraft would not contaminate the moon Europa (where there is a possibility of life being found under the icy surface), Galileo was sent plunging into Jupiter in 2003.

GASPRA

MAGELLAN 1989 : PROBE TO VISIT VENUS

During its four years in polar orbit around Venus, the spacecraft radar-mapped 98% of the surface and collected high-resolution gravity data of Venus.

Picture credit : NASA/JPL

Picture credit : NASA/JPL

Computer generated view of the volcanoes Sif Mons (left) and Gula Mons (right)

The purpose of the crash landing in 1994 at the end of the mission was to gain data on the planet's atmosphere and on the performance of the spacecraft as it descended.

Once the radar data had been received, a map of the surface could be produced – the surface could not be seen due to dense cloud cover

Red = mountainsPurple = low lying land

Using computers, pictures of the p lanet sur face were then generated, as seen below

CASSINI – HUYGENS 1997 : PROBE TO VISIT SATURN AND ITS MOONS

Cassini is an orbiter flying around Saturn, which continues to study surface geology of moons, weather patterns, the magnetic field/solar wind interactions and a detailed analysis of Saturn’s rings.

CASSINI'S LEGACY

! Photographed many moons of Saturn

! The moon Enceladus has an atmosphere

! Detailed study of Saturn’s rings

Picture credit : ESA/NASA/JPL/University of Colorado LASP

Computer generated colours added to a UV image of Saturn’s Rings

Landing – by a lander or remote-controlled cars. Huygens landed on Titan in January 2005, giving us important data about the atmosphere of Titan and the first pictures of the moon’s surface.

HUYGEN'S LEGACY ! Photographed the surface of Titan

Picture credit : ESA/NASA/JPL/University of Arizona

! Findings about the atmosphere of Titan The atmosphere is rich in nitrogen and was thought to be similar to the Earth’s atmosphere billions of years ago.

After the success of the Mars Pathfinder Mission, NASA landed two rover cars, Spirit and Opportunity. Initially with a planned 90 days activity on the surface of Mars, both cars have performed so well that 4 years on the cars are still gaining details about the Martian surface. The following is one of the staggering number of superb images taken by the Spirit rover near the rim of Gusev crater.

Picture credit : NASA/JPL/Texas A&M/Cornell

Sunset on Mars : the Sun is only 2/3rd the size seen from Earth

The Mars Phoenix Mission landed a spacecraft at the north polar region of the planet. The remote controlled arm collected samples of Martian soil from below the surface for analysis in a tiny onboard laboratory. The aim was to investigate the history of water in the region. Evidence for a habitable zone was sought, as well as looking at the chemicals in the ground to see the potential for living things in the Martian environment.

Impact collision – this is where a space probe is deliberately crashed on to the surface of an object, as with the Deep Impact mission which hit comet Tempel 1. This mission discovered more about the chemical nature of a comet as debris was scattered from its surface at impact. Another part of the probe filmed the collision of the impactor with the comet:-

Picture Credit : NNASA/UM M. F. A'Hearn et al., Science 310, 258 (2005); published online

8 September 2005 (10.1126/science.1118923). Reprinted with permission from AAAS.

Collecting and returning - The Japanese probe ‘Hayabusa’ landed on asteroid Itokawa twice in September 2005. Samples have been obtained and were brought back to Earth when the sample capsule landed in Australia in 2010.

Picture credit : ISAS/JAXA

A robot's shadow on asteroid Itokawa