Brilliant Venus in west dusk until mid-evening. Venus – brightest planet and third-brightest object in the sky after the sun and moon – climbs higher up at dusk, and stays out later after dark, than it did in March 2015.
Do not miss the sky at nightfall, around April 11. It’s your chance to see the sky’s brightest planet coupling up with the Pleiades star cluster. Bring your binoculars, if you have them to view Venus and the Pleiades taking stage in a single binocular field. Read more about this special sky event here.
The waxing crescent moon swings close to Venus for several days, centered on April 21.
Throughout April 2015, brilliant Venus beams like a lighthouse as darkness falls! Be sure to catch Venus at dusk and early evening from temperate latitudes in the Southern Hemisphere, because this world follows the sun beneath the horizon by early evening. At mid-northern latitudes, Venus stays out longer after dark, possibly until after your bedtime.
At mid-northern latitudes, this dazzling world sets about three hours after sunset in early April. The queen planet’s visibility improves throughout April, setting about three and one-half hours after the sun by the month’s end.
Fading Mars sets soon behind the sun. Mars has lingered in our western twilight sky for many months, and it continues to fade in brightness, falling into the sunset glare. It’s farther and farther below Venus each evening.
But you might see Mars still, with or without binoculars, when the young waxing crescent moon pairs up with Mars on April 19. See the moon that night, but not Mars? Then use your binoculars to sweep near the moon!
Why is the Red Planet getting dimmer and dropping into the sunset now? It’s because Mars is now lagging far behind Earth in its larger and slower orbit. Soon, Earth will be so far ahead of Mars in orbit that the sun will be between us and it. Mars will pass behind the sun, thereby entering our morning sky, on June 14. But we won’t see much of Mars between now and June. The bright glare of the sunset will hide it from our view long before its June conjunction with the sun. You might see Mars near the moon on April 19. It’ll surely be gone shortly after that.
Like a fading ember, this world is slowly but surely disappearing into the glow of sunset this month, as our planet Earth races ahead of Mars in its orbit.
Bright Jupiter from dusk until late night. Once you see Jupiter at dusk or nightfall, you won’t mistake it for anything else. Look southward as darkness falls from Northern Hemisphere locations; look northward as darkness falls from Earth’s Southern Hemisphere.
Jupiter shines more brilliantly than any star. It’s the second-brightest planet after Venus. In April 2015, Venus sets in the west at early-to-mid evening, leaving the king planet Jupiter to rule the night until the wee hours of the morning. Jupiter goes westward throughout the night; and at mid-northern latitudes, sets in the west about two hours before sunrise in early April, and by the month’s end, sets about three hours before sunup.
If you have binoculars or a telescope, be sure to check out Jupiter’s four major moons, which look like pinpricks of light on or near the same plane. They are often called the Galilean moons to honor Galileo, who discovered these great Jovian moons in 1610. In their order from Jupiter, these moons are Io, Europa, Ganymede and Callisto.
These moons circle Jupiter around the Jovian equator. In cycles of six years, we view Jupiter’s equator edge-on. So, in 2015, we get to view a number of mutual events involving Jupiter’s moons through a high-powered telescope. Click here or here or here for more details.
Click here for a Jupiter’s moons almanac, courtesy of Sky & Telescope.
Saturn from late night until dawn. At mid-northern latitudes, the golden planet Saturn rises in the southeast around midnight in early April and around 10 p.m. by the month’s end. At temperate latitudes in the Southern Hemisphere, Saturn rises at mid-evening in early April and at nightfall by late April. Watch for the waning moon to shine within the Saturn’s vicinity for a few days, centered around April 7.
Binoculars don’t reveal Saturn’s gorgeous rings. For that, you need a small telescope.
Saturn’s rings are inclined at about 25o from edge-on in April 2015, exhibiting their northern face. Several years from now, in October 2017, the rings will open most widely, displaying a maximum inclination of 27o. As with so much in space (and on Earth), the appearance of Saturn’s rings from Earth is cyclical. In the year 2025, the rings will appear edge-on as seen from Earth. After that, we’ll begin to see the south side of Saturn’s rings, to increase to a maximum inclination of 27o by May 2032.
Mercury at dusk in second half of April. Mercury is our solar system’s innermost planet and always stays near the sun in our sky. As seen from the Northern Hemisphere, the last week of April and the first few weeks of May 2015 will present the best time this year to catch Mercury in the evening sky.
Those at southerly latitudes aren’t quite as lucky this month. As seen from there, the ecliptic – or path of the sun, moon and planets – makes a narrow angle to the evening horizon, keeping Mercury low in the sky after sunset. Try scanning with binoculars, if you’re in a Southern Hemisphere location.
At temperate latitudes in the Northern Hemisphere, this world sets about one and one-half hours after the sun in late April. Starting around April 23 or so, look for Mercury over the sunset point on the horizon as dusk gives way to darkness.
Or try this. Draw an imaginary line from bright Jupiter through even-brighter Venus to locate Mercury near the horizon, starting around 60 to 75 minutes after sunset. What is that line across the sky? It’s the ecliptic – sun and moon’s path – plane of the solar system – of course.
Binoculars are always recommended to enhance sky views! Click here for recommended almanacs. They can help you know when Mercury sets in your sky.
Mercury will stay in the evening sky until nearly the end of May 2015. Then it’ll pass into the morning sky, to give the Southern Hemisphere a favorable morning apparition of Mercury in the second half of June 2015.
What do we mean by visible planet? By visible planet, we mean any solar system planet that is easily visible without an optical aid and that has been watched by our ancestors since time immemorial. In their outward order from the sun, the five visible planets are Mercury, Venus, Mars, Jupiter and Saturn. These planets are visible in our sky because their disks reflect sunlight, and these relatively nearby worlds tend to shine with a steadier light than the distant, twinkling stars. They tend to be bright! You can spot them, and come to know them as faithful friends, if you try.
Bottom line: Three of the five visible planets are in good view throughout April 2015: Venus, Jupiter shine first thing at dusk, and Saturn adorns the late evening and morning hours! Mars fades in the evening sky, whereas Mercury appears in the western dusk during the last week of the month.