Special to CosmicTribune.com, June 2, 2025

Excerpts from weekly Sky&Telescope report.

The waxing Moon passes Mars and Regulus, which are equal in brightness this week but, as ever, different in color.

SUNDAY, JUNE 1

■ Now the Moon leaves Mars behind to get chummy with Regulus, shining only about 1° from it this evening (depending on your location).

But at a distance of 79 light-years, Regulus is 1.9 billion times farther from us than the Moon is.

MONDAY, JUNE 2

■ First-quarter Moon (exact at 11:41 p.m. EDT). After dark the Moon shines between the dim hind feet of Leo: 4th-magnitude Sigma and Rho Leonis. Above the Moon by 15° look for 2nd-magnitude Denebola: Beta Leonis, the lion’s tail tip.

TUESDAY, JUNE 3

■ To most of us, “Cassiopeia” means “Cold!” Late fall and winter are when this landmark constellation stands high overhead (for mid-northern latitudes). But even on warm June evenings, it still lurks low. As twilight fades out, look for it down near the north horizon: a wide, upright W. The farther north you are the higher it’ll appear, but even as far south as San Diego and Atlanta, all of its stars will be above the horizon.

WEDNESDAY, JUNE 4

■ Have you ever seen Alpha Centauri?! At declination –61° our brilliant, magnitude-zero neighbor is permanently out of sight if you’re north of latitude 29°. But if you’re at the latitude of San Antonio, Orlando, or points south, Alpha Cen skims just above your true southern horizon for a little while late these evenings.

When to look? When Alpha Librae, the lower-right of Libra’s two brightest stars, is due south over your landscape. That’s about 10 p.m. now (depending on where you live east-west in your time zone). At that time, drop your gaze 45° straight down from Alpha Lib.

THURSDAY, JUNE 5

■ The waxing gibbous Moon hangs high in the south as the sky darkens after sunset. How soon can you spot 1st-magnitude Spica emerging into view 5° or 6° to its left? When watching for a star or planet to come into view in a bright twilight sky, you’ll look and look and it won’t be there, then suddenly it pops out and stays more or less steadily in view. You wonder why you missed it.

The reason you missed it because the center of your vision had to land precisely on it, by chance, as you patiently searched. That’s because your vision is sharp only at the very center of your retina (the fovea centralis). Away from there your vision gets quite blurry, meaning low-resolution, the more so the farther into your peripheral vision. At low resolution, a tiny bright point blurs away completely if it mixes with a bright background.

And why, exactly, did that take you by surprise?

Because our brain’s visual system does not show us what the eye shows the brain. If it did, wherever you looked you’d see a little patch of sharp detail straight ahead surrounded by more poorly-resolved patches of shape and color growing larger and larger the farther they are into your peripheral vision. This would look like staring down a round tunnel with patterns on its sides: the patterns would look tiny in the distance, and larger and larger the closer they are to you, out to the edges of your vision.

The reason you don’t experience your view being projected on tunnel walls like that (except under psychedelics or near-death brain disturbances) is because our perceptual system evolved to construct a useful, 3-D mental model of our surroundings in their actual space. Your neural model of the world in which you move, an abstract encoding that exists in the few cubic inches your skull, evolved to enable us and other animals to operate successfully in the actual external world. The illusion that we perceive the outside world directly is an unconscious shortcut to save processing power. Else you’d always have to decipher jumbles of tunnel illusions deliberately.

This is another reminder that our conscious experience of reality is a limited information-processing phenomenon — it’s not external reality itself. The two are radically different orders of being. The history of science has been the slow unfolding of this revelation.

And that is why Spica is first not there, then surprisingly suddenly it is.

FRIDAY, JUNE 6

■ After dark, Vega is the brightest star high in the east. Barely lower left of it is 4th-magnitude Epsilon Lyrae, the Double-Double. Epsilon forms one corner of a roughly equilateral triangle with Vega and Zeta Lyrae, as shown below. The triangle is less than 2° on a side, hardly the width of your thumb at arm’s length.

Binoculars easily resolve Epsilon. And a 4-inch telescope at 120× or more should resolve each of Epsilon’s two components into a tight pair.

Zeta Lyrae is also a double star for binoculars, but much tougher. It’s unresolved in the photo below but is plainly an unequal pair in nearly any telescope.

Delta Lyrae, below Zeta, is a much wider and easier pair, gold and blue.

Akira Fujii

SATURDAY, JUNE 7

■ The Big Dipper hangs high in the northwest at nightfall. The Dipper’s Pointers, currently its bottom two stars, point lower right toward Polaris. Above Polaris, and looking very similar to it, is Kochab, the lip of the faint Little Dipper’s bowl. Kochab passes exactly over Polaris around 9:30 or 10 p.m., depending on how far east or west you live in your time zone. Check by comparing them to a vertical line, such as the edge of a building.

SUNDAY, JUNE 8

■ The nearly full Moon (it’ll be full on Tuesday night the 10th) shines well to the upper right of Antares this evening, as shown below. This is the view in twilight. As night advances, the scene moves higher and tips leftward toward the south.

  June 1-8: Epsilon, the double double star near Vega, The Sky