![WHAT IS A LIGHT YEAR?](https://cdn.magzter.com/1493279487/1643218032/articles/61f270ab301f3/WHAT-IS-A-LIGHT-YEAR.jpeg)
A light year is a measurement of distance and not time, as the name might suggest. A light year is the distance a beam of light travels in a single Earth year, or around 9.7 trillion kilometres (6 trillion miles). On the scale of the universe, measuring distances in kilometres or miles just doesn’t cut it. In the same way that you may measure the distance to the supermarket in the time it takes to drive there, astronomers measure the distances of stars in the time it takes for their light to travel to us. For example, the nearest star to our Sun, Proxima Centauri, is 4.2 light years away.
هذه القصة مأخوذة من طبعة Issue 126 من All About Space.
ابدأ النسخة التجريبية المجانية من Magzter GOLD لمدة 7 أيام للوصول إلى آلاف القصص المتميزة المنسقة وأكثر من 9,000 مجلة وصحيفة.
بالفعل مشترك ? تسجيل الدخول
هذه القصة مأخوذة من طبعة Issue 126 من All About Space.
ابدأ النسخة التجريبية المجانية من Magzter GOLD لمدة 7 أيام للوصول إلى آلاف القصص المتميزة المنسقة وأكثر من 9,000 مجلة وصحيفة.
بالفعل مشترك? تسجيل الدخول
![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