HELLO GAZERS OF THE STARS, TRACE HERE WE JUST PASSED PERIHELION -- THE MOMENT WHERE EARTH REACHES ITS CLOSEST ORBITAL POINT AT EXACTLY 1:52AM EASTERN -- BUT ASTRONOMERS DON T USE EASTERN TIME, THEY USE COORDINATED UNIVERSAL TIME!

A DAY IN UTC CONTAINS EXACTLY 86,400 SECONDS, EXCEPT WHEN THEY NEED A LEAP SECOND BECAUSE EARTH S ORBIT IS IMPFECT.

THEY MEASURE THOSE SECONDS USING ATOMIC CLOCKS ALL OVER THE WORLD.

IT S SO PRECISE THAT WE CAN MEASURE FRACTIONS OF SEC-ONDS LOST DUE TO TIME DILATION EFFECTS ON FAST-MOVING SPACECRAFT AS DESCRIBED BY EINSTEIN S THEORY OF RELA-TIVITY.

BREATHE IT S WILD.

POP OUT AT 10AM UTC AND LOOK EAST TO FIND ARCTURUS AND BOOTES HERDSMAN!

STOP UTC IS USEFUL BECAUSE SOME OF THE SKY IS VISIBLE SOME-WHERE AT ALL TIMES.

NOTATING AN EVENT IN UTC TELLS AS-TRONOMERS EXACTLY WHEN AN EVENT OCCURRED.

NO CON-VERTING FOR DAYLIGHT SAVING OR TIME ZONES.

KEEP LOOKIN UP!