This simulated 7×50 binocular view shows the configuration of the rising 17-day-old waning gibbous Moon, largest planet Jupiter and first-magnitude star Spica in the constellation of Virgo at 10pm GMT on Tuesday 14 March 2017. The trio lie low in the east-southeast as seen from the British Isles at this time. AN graphic by Ade Ashford.If skies are clear on the night of Tuesday 14 March, look to the southeast around 10pm local time to see the 17-day-old Waning gibbous Moon in the same binocular view as planet Jupiter. As seen from the UK and Western Europe, the pair lie just 2 degrees apart. In low-power binoculars you’ll be able to fit first-magnitude star Spica — the primary luminary of the constellation Virgo — into the field of view too!
As viewed from the east coast of North America at 10pm local time, the Moon-Jupiter separation will have grown to 3.7 degrees, but the celestial triumvirate of Moon, planet and star will still make a beautiful grouping in low-power binoculars.
Jupiter is less than a month from opposition (7 April), so it’s very much open season for the Solar System’s largest planet. Now shining at magnitude -2.4, its mighty equator spans 43.3 arcseconds, meaning that a telescope magnifying just 42x is sufficient to enlarge it to the same apparent size of the adjacent Moon to the naked eye.
The apparent proximity of the Moon and Jupiter is, of course, a line of sight effect. The planet lies 423 million miles (681 million kilometres) from Earth on the night of 14 March — some 1,720 times farther away than the Moon.This computer simulation shows the configuration of Jupiter and its four large Galilean moons Io, Europa, Ganymede and Callisto at 10pm GMT on 14 March. This is an erect-image view (north up, east left) corresponding to a high-power binocular or terrestrial telescope. Users of Newtonian reflectors (including Dobsonians) need to rotate this view 180 degrees. Those using refractors and Schmidt- or Maksutov-Cassegrain telescopes with a star diagonal should mirror the image left-right to match their eyepiece views. AN graphic by Ade Ashford.If you have the clear skies and stamina to stay up in the UK, Jupiter’s Great Red Spot will be visible on the planet’s eastern limb by 2am GMT on 15 March and the GRS transits shortly after 3am GMT. The Great Red Spot will be close to Jupiter’s central meridian again at 11pm GMT on 15 March.
For predictions of GRS transits and phenomena of Jupiter’s Galilean moons Io, Europa, Ganymede and Callisto for other dates, times and locations, please consult our interactive online Almanac and ensure that the ‘Add phenomena of Jupiter?’ box is checked.
Inside the magazine
For a comprehensive guide to observing all that is happening in the coming month’s sky, tailored to Western Europe and North America, obtain a copy of the March 2017 edition of Astronomy Now.
In many ways stars are like living beings. They’re born; they live; they die. And they even have a heartbeat. Near the end of their lifetime they begin to pulsate, increasing and decreasing their brightness by a large amount every few hundred days. Using a novel technique, astronomers have detected thousands of stellar “pulses” in the galaxy Messier 87 (M87). Their measurements offer a new way of determining a galaxy’s age.
Jupiter, the solar system’s largest planet, is now visible low in the southeast three hours after darkness falls in the UK. Now’s the time to dust off your telescope, check its optical alignment and hone your Jovian observing skills – particularly since a series of double shadow transits of the planet’s large Galilean moons starts on 24 March 2018.
There’s a lot of planetary activity in the dawn sky in mid-April. If you’re an early riser in the British Isles, let the waning crescent Moon be your guide to the naked-eye planets Jupiter, Saturn and Mars on 15 and 16 April 2020. Typical 7×50 or 10×50 binoculars will show these attractive conjunctions well, while the smallest of telescopes also reveal some of Jupiter’s bright Galilean moons.
