Summer solstice marks longer days, but we're not closer to the sun
Posted June 20, 2018 9:38 p.m. EDT
Updated June 21, 2018 12:06 a.m. EDT
On Thursday June 21, 2018 at 6:07 a.m. EDT, the sun will be directly over the tropic of Cancer, at 23.5 degrees north latitude, marking the June solstice and the beginning of astronomical summer.
The North Pole will be at its most tilted toward the sun, which is why days are at their longest now.
The tilt makes for longer days in the northern hemisphere. On Thursday, Raleigh will receive about 14 hours, 35 minutes of sunlight.
As we pass the solstice, the sun wont make it quite as high in the midday sky, but will rise a little later and set a little earlier each day. Differences are small at first, just a few seconds through the end of June, but will accelerate as we approach the equinox in September.
Temperatures in the 90s this week may make us feel that much closer to the sun, but we are actually near the furthest point from the sun for the year. Earth reaches aphelion on July 6. This means the Earth is more than 3.1 million miles further from the sun than perihelion, the closest point, on Jan. 3.
Keep that in mind the next time you read a claim on Facebook that "If the Earth was 10 feet closer to the sun we would all burn up and if it was 10 feet further we would freeze to death.” Right now, the Earth is moving that 10 feet further away from the sun every 2 seconds.
You might have recently noticed the bright point of light after sunset in the southern sky. Jupiter will continue to dominate the evening sky throughout the summer and will be joined by Saturn in mid-July, followed by Mars in August.
Friday night, look for Jupiter, the moon and the bright star Spica to form a triangle in the southwestern sky after sunset. The orange star to the left may look a bit like Mars, but that is Antares, which is more than 72 million times further away than Mars. Look again Saturday for Jupiter and the moon to appear even closer.
Tony Rice is a volunteer in the NASA/JPL Solar System Ambassador program and software engineer at Cisco Systems. You can follow him on twitter @rtphokie.