Bob Berman

This week’s half Moon will appear unusually low in the sky—so low it might be hidden behind the trees. It sits far below its usual path due to the Moon’s wobbling orbit, which currently aligns with Earth’s tilt. This rare positioning, part of a cycle called the Lunar Standstill, places the Moon near the constellation Scorpius and its bright star Antares. Its light, filtered through thick atmosphere, may appear honey-colored and cast moonbeams at odd angles into places that rarely see moonlight. Look south to see this striking celestial oddity.

Arcturus: A Star Worth Saluting: On the next clear evening around 8 p.m., look west and halfway up the sky—you’ll spot Arcturus, a bright pastel-orange star and the fourth brightest we can see from Earth. It once famously opened the 1933 Chicago World's Fair with its light and is unique among bright stars for its wild, plunging path through space. Unlike stars that circle with the Milky Way, Arcturus is just passing through—so catch a glimpse while you can. It's the brightest thing in tonight’s sky… and it won’t be there forever.

Wednesday August 13 around 5:15–5:30 a.m., early risers with a clear view of the eastern horizon can witness a rare celestial lineup: the crescent Moon alongside Venus—the dazzling Morning Star—with Jupiter shining above and Mercury low near the horizon. This nearly vertical arrangement of the three brightest night sky objects, plus elusive Mercury, happens only in late summer and early fall when the solar system’s plane aligns upright at dawn—making it well worth setting an early alarm.

The Perseid meteor shower has begun. While the best viewing typically occurs after midnight when your location faces forward into the meteor stream, this year’s full moon is bright enough to interfere with visibility. To get around this, it's best to start watching at dusk, before the moon rises. The Perseids are tiny bits of ice from comet Swift Tuttle, disintegrating as they enter Earth's atmosphere. About one in 20 meteors, however, is a background meteor from the asteroid belt, which can survive their fiery descent. These "sturdy" meteors can even crash through roofs at speeds of up to 250 miles per hour. Despite the rarity of such impacts, insurance usually covers the damage.

We explore the quirky world of units—from the 1999 Mars Orbiter disaster caused by a metric vs. imperial mix-up to the colorful ways we measure everything from chili pepper heat to cotton and paper. You'll learn why U.S. territorial waters were once based on the range of a cannon shot, how Fahrenheit’s scale reflects geometric symmetry, and why a "barrel" of oil isn’t the same as a barrel of beer. With oddball units like skeins, quires, and cords still in use, maybe it’s finally time we all bolted over to metric!

On Wednesday, July 23, we saw a rare cosmic pairing as the Moon passes unusually close to Spica, the brilliant blue star in Virgo. Thanks to a unique tilt in the Moon’s orbit — an event that won’t repeat until 2043 — this striking alignment becomes visible to the naked eye. Learn why Spica shines so hot and bright, and how to pronounce its name the right way. Look up between 9:30 and 10 p.m. for a glimpse of this fleeting spectacle.

This week marks the statistically hottest time of the year—a fitting moment to reflect on the nature of heat. At its core, heat is just atomic motion: room temperature atoms zip around at 1,000 mph, and even freezer-chilled ones aren't far behind. Combustion happens when atoms move fast enough to sustain a reaction, with ignition temperatures varying by substance—wood around 400°F, gasoline at 495°F, and paper at the symbolic 451°F. Pyrophoric materials like sodium don’t even need a spark to ignite. Ultimately, heat is motion—your feverish 102°F body is just your molecules moving faster than usual. Tune in this week to hear more about atomic speed.

Twelve years ago, NASA's Curiosity rover journeyed to Mars with instruments that measured space radiation for the first time en route. The findings were sobering: astronauts would face radiation doses equivalent to a full-body CT scan every few days—raising cancer risks by 3–4% on the trip alone. Most of this came from galactic cosmic rays, which spacecraft walls can’t block. And this didn’t even include the added threat of solar storms. To send humans safely to Mars, solving the radiation challenge is essential.

Set your alarm early this week and look east between 5:00 and 5:30 a.m. to catch a stunning celestial display. Brilliant Venus, the Morning Star, shines high with the bright orange star Aldebaran glowing below. Aldebaran, part of the V-shaped Hyades cluster in Taurus, has a rich astronomical legacy—its position once helped confirm Einstein’s theory of General Relativity. Nearby, you’ll also spot the shimmering Pleiades cluster. Together, these stars create a breathtaking, layered view of the cosmos worth waking up for.

Celestial Visitor: Mars. You’ll see a bright "star" near the Moon, Mars — the planet long blamed for alien invasions in fiction. While Martian fears have faded, real space threats remain, like rogue asteroids. In 2013, one zipped past Earth while another exploded over Russia, injuring over a thousand. However, the ultimate doomsday scenario won’t come from space rocks, pandemics, or even climate change — it’ll come from our own Sun. In about 1.1 billion years, the Sun’s growing heat will boil Earth’s oceans, ending life as we know it. So, enjoy the night sky… while you can (you've got time).