Hayabusa2’s mission has been to study Ryugu and to also carry four separate landers to investigate the comet’s surface Why Explore Our Solar System is made up of the Sun eight planets and their moons at least five dwarf planets millions of asteroids and probably billions of comets Despite knowing all this about our Solar System however there are still many unanswered questions There is a lot to discover Human and robotic exploration will help find answers Learning More The Japanese Hayabusa2 spacecraft arrived at the asteroid Ryugu on June 27 2018 A few months later it sent a lander to collect samples from the asteroid After Hayabusa2 left the asteroid it began to travel back to Earth When it arrives scientists will study the samples the spacecraft collected These samples may help them understand how asteroids formed in the early years of our Solar System Research such as this expands our understanding of our Solar System Focus of Innovation Space exploration also helps drive new ideas on Earth Some of the technology developed to build the spacecraft and have it land on an asteroid will filter down to have an impact on different aspects of everyday life 6
MISSION Space Science NASA’s OSIRIS-REx was launched in September 2016 to land on an asteroid named Bennu just over two years later Bennu is a small asteroid measuring 1,600 feet 488 m in diameter It was selected as a target from more than 500,000 known asteroids because it is close to Earth Its ancient rocks may hold clues to the origin of life Its surface of loose soil dust and broken rock should be easy for a lander to collect OSIRIS-REx returned its first images of Bennu in August 2018 when it was still 1 4 million miles 2 2 million km away Its influence could include anything from new materials for the transportation industry to communications systems and advances in computer technology New Partnerships The challenges of exploring space are driving new partnerships between governments industries universities and research centers around the world Hayabusa2’s lander MASCOT is operated by the German Aerospace Center DLR and the French Space Agency FSA The agencies consulted 100 international and national partners before choosing a final landing site on Ryugu This artwork imagines asteroids surrounding a young planet when our Solar System was new 7
The Sun Like about 10 percent of the other stars in the Milky Way galaxy our CHAPTER 2 Sun is a yellow dwarf star A yellow dwarf is a medium-sized star The Sun is a bright hot ball made up of hydrogen and helium Hydrogen undergoes a nuclear reaction to form helium generating heat at the same time The Sun is 864,000 miles 1 4 milion km in diameter That is more than 100 times as wide as Earth Around 1 3 million Earths would fit inside the Sun Temperatures on the Sun range from 10,000 Fahrenheit 5,540 C on the surface to around 27 million Fahrenheit 15 million C at the center 8 Superstrong Sun The Sun holds our Solar System together Its gravity keeps everything in orbit from large planets such as Jupiter to tiny pieces of space dust Earth is only the third planet from the Sun and it is 93 million miles 150 million km away Distances in our Solar System are usually measured in astronomical units AU One AU is the distance from Earth to the Sun Neptune is about 30 AU from the Sun Sedna is another orbiting object discovered in 2003 Its distance from the Sun varies between 76 AU and 940 AU The Sun and the rest of our Solar System formed In this view of the Sun’s surface the bright spots are giant storms on the Sun that are bigger than Earth
The Sun releases more energy in 1 5 millionths of a second than everyone on Earth uses in a year from a giant spinning cloud of gas and dust about 4 5 billion years ago There was so much gravity that the cloud collapsed in on itself spinning faster and faster and flattening out Most of the material was pulled toward the center It formed our Sun and the other material formed the planets moons and other objects The Sun makes up 99 8 percent of the mass of our entire Solar System Copycats Hydrogen makes up most of the Sun’s mass It is under so much pressure that hydrogen atoms hit each other with such force that they blend together to form a different element called helium This process is called nuclear fusion and it releases vast amounts of energy Scientists are trying to scale down this process so they can use it in a new wave of nuclear fusion reactors to produce electricity here on Earth 9
