FRIDAY, MARCH 27
■ Cassiopeia, that signature fall-and-winter constellation of the northern sky, now retreats down after dark. Look for it fairly low in the north-northwest. It’s standing roughly on end (its brighter end).
But for skywatchers at mid-northern latitudes and farther north, Cassiopeia is circumpolar: never going away completely. By 1 or 2 a.m. daylight-saving time it will be at its lowest due north, lying like a not-quite-horizontal W.
Unless, that is, you’re south of about latitude 25° N. Seen from there it skims below the north horizon.
SATURDAY, MARCH 28
■ The huge, bright Winter Hexagon is still in fine view early after dark. It fills the south and southwest sky from low to almost overhead: from Rigel in Orion’s foot to Pollux and Castor on high, and all the way from Sirius to Capella.
Start with brilliant Sirius in the southwest, the Hexagon’s lower left corner. High above Sirius is Procyon. From there look higher to the upper right for Pollux and Castor (with Jupiter trying to steal their show). Next go lower right from Castor to 2nd-magnitude Menkalinan and then bright Capella, lower left from there to Aldebaran, then lower left to Rigel, and back to Sirius.
The Hexagon is somewhat distended. But if you draw a line through its middle from Capella to Sirius, the “Hexagon” is fairly symmetric with respect to that long axis.
The Hexagon encompasses most of the bright “winter” stars.
SUNDAY, MARCH 29
■ The waxing gibbous Moon shines in Leo tonight. The Lion’s bright forefoot, Regulus, glitters about 4° to the Moon’s upper right after dark. Regulus is the handle-end of the Sickle of Leo. The rest of the Sickle stands up from Regulus, by about a fist at arm’s length. It’s open toward the right.
Leo’s hindquarters and tail are a long right triangle about a fist left of the Moon.
■ This is the time of year when the dim Little Dipper juts toward the right from Polaris (the Little Dipper’s handle-end) during evening. The much brighter Big Dipper curls high above it, “dumping water” into it. They do the reverse water dump in the fall.
MONDAY, MARCH 30
■ Now the Moon, just two days from full, shines below the center of Leo.
On the Moon itself, the sunrise terminator has nearly reached the Moon’s celestial-east limb. Here the terminator runs across the vast, mostly flat expanse of Oceanus Procellarum. But, with a telescope or even good binoculars, do you see that little bright white spot on the gray expanse very close to the terminator, due east from the Moon’s center? (Turn off your telescope’s drive, if any; the field will drift from east toward west.) That is the crater Aristarchus, relatively young, made by an impact 450 million years ago. It is the brightest easily visible feature on the Moon.
In 1651, when the invention of the telescope was still in living memory, Giovanni Riccioli named this brightest lunar mark for the Greek astronomer Aristarchus of Samos. Far ahead of his time, Aristarchus used careful naked-eye observations and basic geometry to correctly figure out the Moon’s rough distance and size. From this, and from the fact that the Moon is very close to 90° from the Sun when it’s exactly half lit (as best as he could determine), he proved that the Sun was many times farther away from us than the Moon is and thus that the Sun had to be at least seven times larger than Earth.
This brilliant early step toward a Copernican understanding of the cosmos, mostly forgotten for 1,800 years until Copernicus himself, may have been what inspired Riccioli to put Aristarchus’s name on the Moon’s brightest feature.
It’s not far from the larger and more obvious bright crater, closer to the Moon’s center and surrounded by a big splash of rays, that he named Copernicus.
TUESDAY, MARCH 31
■ High above the Big Dipper late these evenings, nearly crossing the zenith, are three pairs of dim naked-eye stars, all 3rd or 4th magnitude, marking the Great Bear’s feet. They’re also known as the Three Springs (or Leaps) of the Gazelle, from early Arab lore. They form an east-west line that lies roughly midway between the bowl of the Big Dipper to their north and the Sickle of Leo to their south. The line is 30° (three fists) long. See the evening constellation chart in the center of the April Sky & Telescope.
According to the ancient Arabian story, the gazelle was drinking at a pond — the big, dim Coma Berenices star cluster — and bounded away when startled by a flick of Leo’s nearby tail, Denebola. Leo, however, seems quite unaware of this, facing the other way.
Another version of the tale sees Coma Berenices as Leo’s extended tailtip and the watering hole as formed by stars in Ursa Major.
WEDNESDAY, APRIL 1
■ Full Moon (exactly full at 10:12 p.m. EDT). The Moon is in Virgo. Look for springtime Spica about one fist below it and the “Spring Star” Arcturus, brighter, about three fists to the Moon’s left.
■ On this special date only, Orion flips upside down. Think photo opportunity.
THURSDAY, APRIL 2
■ Now the Moon, a day past full, is just a couple of degrees below Spica. Cover the Moon with your hand to hide its glare.
FRIDAY, APRIL 3
■ The Pleiades are still high in the west at nightfall, as shown below. Their April descent toward Venus is now under way.
Far above it, once the sky becomes dark enough, the Pleiades glitter to the lower right of brighter, orangy Aldebaran. Tonight the Pleiades are 25° above Venus. Watch them close in on each other by almost 1° per day until they pass each other, 3¾° apart, on April 23rd and 24th.
■ Callisto, Jupiter’s slowest-moving large satellite, casts its tiny black shadow onto Jupiter’s face from 9:14 p.m. EDT to 1:32 a.m. EDT tonight. Callisto itself is a good two or three Jupiter-diameters to Jupiter’s west.
Meanwhile, Jupiter’s Great Red Spot should transit the planet’s meridian around 9:48 p.m. EDT.
SATURDAY, APRIL 4
■ Shortly after the end of twilight around this time of year, Arcturus, the bright Spring Star climbing in the east, stands just as high as Sirius, the even brighter Winter Star descending in the southwest, for skywatchers not far from 40° north latitude.
These are the two brightest stars in the sky at the time. But Capella is a very close runner-up to Arcturus! Spot it high in the west-northwest.
SUNDAY, APRIL 5
■ Capella, high in the west-northwest during and after dusk, has a pale yellow-white color matching the Sun’s — meaning they’re both about the same temperature. But otherwise Capella is very different. It consists of two yellow giant stars orbiting each other every 104 days.
Moreover, for telescope users, it’s accompanied by a distant, tight pair of red dwarfs: Capella H and L, magnitudes 10 and 13. Article and finder charts.
This Week’s Planet Roundup
Mercury and Mars are low in the glare of sunrise.
Venus, bright at magnitude –3.9, gleams low in the evening twilight, a little less low each week. Look for it due west. Forty minutes after sunset this week it will still be about a fist at arm’s length above horizontal. It sets at twilight’s end.
Jupiter is bright and easy, nearly overhead when you face south as the stars come out. Jupiter shines at magnitude –2.2, making it the brightest point in the sky after Venus sets. Jupiter soon shifts to the very high southwest, then moves lower as the evening grows late. It sets around 3 a.m. daylight-saving time on the west-northwest horizon.
In a telescope Jupiter is 40 arcseconds wide. It’s shrinking and fading as Earth pulls farther ahead of it in our faster orbit around the Sun.
Even a small telescope can show, during good seeing, that the North Equatorial Belt is slightly darker and narrower than the South Equatorial Belt. Note the small dark red oval in the NEB’s north edge, at nearly the same longitude as a similar-sized white oval in the latitude of the South South Temperate Belt.
Saturn and Neptune are out of sight in conjunction with the Sun.
Uranus (magnitude 5.8 in Taurus, 4° SSW of the Pleiades) is still some 30° high in the west at the end of twilight. At high power in a telescope it’s a tiny but non-stellar dot, 3.5 arcseconds wide. You’ll need a detailed finder chart to identify it among similar-looking faint stars.
All descriptions that relate to your horizon — including the words up, down, right, and left — are written for the world’s mid-northern latitudes. Descriptions and graphics that also depend on longitude (mainly Moon positions) are for North America. Eastern Daylight Time (EDT) is Universal Time minus 4 hours. UT is also known as UTC, GMT, or Z time.
Want to become a better astronomer? Learn your way around the constellations. They’re the key to locating everything fainter and deeper to hunt with binoculars or a telescope.
This is an outdoor nature hobby. For a more detailed constellation guide covering the whole evening sky, use the big monthly map in the center of each issue of Sky & Telescope, the essential magazine of astronomy.
For the attitude every amateur astronomer needs, read Jennifer Willis’s Modest Expectations Give Rise to Delight.
Once you get a telescope, to put it to good use you’ll want a much more detailed, large-scale sky atlas (set of charts). The basic standard is the Pocket Sky Atlas, in either the original or Jumbo Edition. Both show all 30,000 stars to magnitude 7.6, and 1,500 deep-sky targets — star clusters, nebulae, and galaxies — to search out among them.
Next up is the larger and deeper Sky Atlas 2000.0, plotting stars to magnitude 8.5; nearly three times as many, as well as many more deep-sky objects. It’s currently out of print, but maybe you can find one used.
The next up, once you know your way around well, are the even larger Interstellarum Deep-Sky Atlas (with 201,000+ stars to magnitude 9.5 and 14,000 deep-sky objects selected to be detectable by eye in very large amateur telescopes), and Uranometria 2000.0 (332,000 stars to mag 9.75, and 10,300 deep-sky objects).
Read How to Use a Star Chart with a Telescope. It applies just as much to electronic charts on your phone or tablet — which many observers find handier and more versatile, if sometimes less well designed and contextualized, than charts on paper.
You’ll also want a good deep-sky guidebook. A beloved old classic is the three-volume Burnham’s Celestial Handbook. It was my bedside reading for years. An impressive more modern one is the big Night Sky Observer’s Guide set (2+ volumes) by Kepple and Sanner. The pinnacle for total astro-geeks is the new Annals of the Deep Sky series, currently at 11 volumes as it works its way forward through the constellations alphabetically. So far it’s up to H.
Can computerized telescopes replace charts? Well, I used to say this:
“Not for beginners, I don’t think, unless you prefer spending your time getting finicky technology to work rather than learning how to explore through the sky yourself. As Terence Dickinson and Alan Dyer say in their Backyard Astronomer’s Guide, ‘A full appreciation of the universe cannot come without developing the skills to find things in the sky and understanding how the sky works. This knowledge comes only by spending time under the stars with star maps in hand and a curious mind.’ Without these, ‘the sky never becomes a friendly place.’ “
But, things change. The technology has continued to improve and become more user-friendly — particularly with software that can now recognize any star field to determine exactly where the telescope is pointed — finally bypassing all aiming imperfections in the mount, tripod, gears, bearings and other mechanics, or in the user’s skill in setting up.
The latest revolution is the rise of small, imaging-only “smartscopes.” These take advantage of not only today’s pointing technology, but also the vastly better capabilities of imaging chips and image processing compared to the human retina and visual cortex. The most sophisticated image stacking and processing can also come built right in. The result is decent deep-sky imaging from shockingly small, low-priced units. The image may be viewable on your phone or computer as it builds up in real time. Some can directly enable contributions to citizen-science projects.
Smartscopes are changing the hobby at the entry level. For more on this revolution see Richard Wright’s “The Rise of the Smart Telescopes” in the November 2025 Sky & Telescope. And read the magazine’s review of this especially small one.
If you get a larger, more conventional computerized scope that you can look through, make sure that its drives can be disengaged so you can swing it around and point it readily by hand when you want to, rather than only slowly by the electric motors (which eat batteries).
Audio sky tour. Out under the evening sky with your
earbuds in place, listen to Kelly Beatty’s monthly
podcast tour of the naked-eye heavens above. It’s free.
“The dangers of not thinking clearly are much greater now than ever before. It’s not that there’s something new in our way of thinking, it’s that credulous and confused thinking can be much more lethal in ways it was never before.”
— Carl Sagan, 1996
“Facts are stubborn things; and whatever may be our wishes, our inclinations, or the dictates of our passion, they cannot alter the state of facts and evidence.”
— John Adams, 1770
“Truly, whoever can make you believe absurdities can make you commit atrocities.”
— Voltaire, 1765
