![BEYOND THE SOLAR SYSTEM](https://cdn.magzter.com/1493279487/1652947335/articles/h3SzA94hw1654257586498/BEYOND-THE-SOLAR-SYSTEM.jpg)
When NASA's Cassini mission to Saturn ended in 2017, the spacecraft was deliberately destroyed by crashing it into the planet. The next year, at the end of the Dawn probe's exploration of the asteroid belt, it was placed in a graveyard orbit around the dwarf planet Ceres. These are the two most common fates of interplanetary missions, but there's a third possibility. If a probe has sufficient speed to carry it out of the Solar System and into the space between stars, it can keep travelling forever.
Five probes have ended up on interstellar trajectories so far. Although their designers knew this would happen, it wasn't their main purpose. The first four - Pioneer 10 and 11 and Voyager 1 and 2 - were launched in the 1970s to study the Solar System's outer planets. More recently they've been joined by New Horizons, launched in 2006 en route to the Kuiper Belt, where it flew past Pluto in 2015 and Arrokoth in 2019.
Pinning down the edge of the Solar System isn't easy. By some definitions it might include the Oort Cloud, which surrounds the Sun at a great distance. By common convention, however, 'interstellar space' starts at a point called the heliopause. This is where the Sun's non-gravitational effects - its magnetic field and the solar wind - cease to be discernible against the background of the interstellar medium.
Voyager 1 passed this point in 2012, followed by Voyager 2 in 2018. The other three probes will follow over the next few decades, although we don't know exactly when, as the heliopause tends to drift about in an unpredictable way.
VOYAGER 1 & 2 THE GRAND TOUR
Diese Geschichte stammt aus der Issue 130-Ausgabe von All About Space.
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Diese Geschichte stammt aus der Issue 130-Ausgabe von All About Space.
Starten Sie Ihre 7-tägige kostenlose Testversion von Magzter GOLD, um auf Tausende kuratierte Premium-Storys sowie über 8.000 Zeitschriften und Zeitungen zuzugreifen.
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![LONG AGO, A LAKE ON MARS MAY HAVE BEEN SPRAWLING WITH MICROBES](https://reseuro.magzter.com/100x125/articles/15256/1729654/KBMk_Cfs41719993738326/LONG-AGO-A-LAKE-ON-MARS-MAY-HAVE-BEEN-SPRAWLING-WITH-MICROBES.jpg)
LONG AGO, A LAKE ON MARS MAY HAVE BEEN SPRAWLING WITH MICROBES
Curiosity discovered manganese oxide in bedrock in a Martian region that may have been a shoreline billions of years ago
![MOON TOUR HELL](https://reseuro.magzter.com/100x125/articles/15256/1729654/ht0gO_mHi1719993459712/MOON-TOUR-HELL.jpg)
MOON TOUR HELL
Finding this fascinating crater isnt as hard as its name suggests...
![THIS MONTH'S PLANETS](https://reseuro.magzter.com/100x125/articles/15256/1729654/-7K-H52mO1719993250345/THIS-MONTHS-PLANETS.jpg)
THIS MONTH'S PLANETS
Most of the planets are tricky targets this month, but our guide will help you locate them
![UNIVERSE BEFORE TIME](https://reseuro.magzter.com/100x125/articles/15256/1729654/cHFLjjJOS1719991851680/UNIVERSE-BEFORE-TIME.jpg)
UNIVERSE BEFORE TIME
Could the existence of a mirror-image cosmos before the Big Bang solve some of the biggest mysteries in astronomy?
![CLIMATE CHANGE IN THE SOLAR SYSTEM](https://reseuro.magzter.com/100x125/articles/15256/1729654/Se3Bbyf0G1719991384386/CLIMATE-CHANGE-IN-THE-SOLAR-SYSTEM.jpg)
CLIMATE CHANGE IN THE SOLAR SYSTEM
Alongside Earth, our planetary neighbourhood is changing, but it’s not for the better…
![Stars give tiny planets a gravitational 'squeeze' to strip away their atmospheres](https://reseuro.magzter.com/100x125/articles/15256/1729654/QMnZ5oBmH1719991224194/STARS-GIVE-TINY-PLANETS-A-GRAVITATIONAL-SQUEEZE-TO-STRIP-AWAY-THEIR-ATMOSPHERES.jpg)
Stars give tiny planets a gravitational 'squeeze' to strip away their atmospheres
A scientist has learned more about the violent processes that rip atmospheres away from planets, finding that squashing and squeezing by a parent star can contribute to this process.
![The Milky Way's halo is filled with ‘magnetic doughnuts' as wide as 100,000 light years](https://reseuro.magzter.com/100x125/articles/15256/1729654/zhhazHOyf1719991166108/THE-MILKY-WAYS-HALO-IS-FILLED-WITH-MAGNETIC-DOUGHNUTS-AS-WIDE-AS-100000-LIGHT-YEARS.jpg)
The Milky Way's halo is filled with ‘magnetic doughnuts' as wide as 100,000 light years
The outer halo of the Milky Way is filled with magnetic fields that take the shape of vast doughnuts with diameters ranging from 12,000 to 100,000 light years, with the heart of our galaxy at their centre.
![The Pentagon wants the commercial space reserve to support military satellites in orbit](https://reseuro.magzter.com/100x125/articles/15256/1729654/RRDjAi68P1719991027212/THE-PENTAGON-WANTS-THE-COMMERCIAL-SPACE-RESERVE-TO-SUPPORT-MILITARY-SATELLITES-IN-ORBIT.jpg)
The Pentagon wants the commercial space reserve to support military satellites in orbit
The US Department of Defense is developing a plan to use the ever-growing American commercial space industry for national security purposes.
![DOES A COSMIC 'GLITCH' IN GRAVITY CHALLENGE ALBERT EINSTEIN'S GREATEST THEORY?](https://reseuro.magzter.com/100x125/articles/15256/1729654/qd-Mswgsf1719990737533/DOES-A-COSMIC-GLITCH-IN-GRAVITY-CHALLENGE-ALBERT-EINSTEINS-GREATEST-THEORY.jpg)
DOES A COSMIC 'GLITCH' IN GRAVITY CHALLENGE ALBERT EINSTEIN'S GREATEST THEORY?
Gravity changes once you reach a cosmic scale
![DEEP SKY CHALLENGE : STELLAR TREASURES OF THE ARCHER AND SCORPION](https://reseuro.magzter.com/100x125/articles/15256/1729654/kQkKImKfQ1719990358327/DEEP-SKY-CHALLENGE-STELLAR-TREASURES-OF-THE-ARCHER-AND-SCORPION.jpg)
DEEP SKY CHALLENGE : STELLAR TREASURES OF THE ARCHER AND SCORPION
Summer skies are stuffed full of amazing objects for your telescope - if you're prepared to stay up late