All posts by Chris Curwin

Europa

~by Chris Curwin, Astronomy by the Bay

Continuing the discussion around some of the unique moons of the solar system… with a look at Europa, one of the four Galilean moons of Jupiter. Easily visible through binoculars or a small telescope, Europa, and Enceladus orbiting Saturn, are in my opinion the best opportunities to discover life elsewhere in our solar system. The pictures below explain why. 😊
(All illustrations / photos courtesy NASA)

NASA image of EuropaEuropa, one of the 69 moons of Jupiter, reveals many crack like features. It has criss crossed layers, leading to theories that below the kilometres of surface ice lies a global sized ocean. It is one of our best opportunities to find life elsewhere in our solar system.

Europa’s Core~

NASA image of Europa's coreEuropa is slightly smaller than our moon, with a smooth and bright surface, and long linear fractures crisscrossing a surface of water ice. Discovered by Galileo in 1610, it is thought to have an iron core like Earth. It is the second closest moon of the 69 known moons orbiting Jupiter.

Gravitational Pull~

Jupiter and its largest moons.The conflicting gravitational pull of Jupiter, Ganymede, Io, and Callisto means that Europa’s orbit changes. The gravitational pulls produce heat, deep within the suspected ocean surface and on the ice surface itself.

Surface Features~

NASA image of Europa's surfaceAbove are some of the examples Europa’s surface. On it’s 3 ½ day elliptical orbit, mighty Jupiter’s gravity tends to create tides that flex Europa’s surface. Flexing causes fractures in Europa’s icy surface, adding heat to the suspected ocean below.

Possible Life in Oceans~

NASA image of possible life in Europa's watersThese tides may also cause hydrothermal or volcanic venting, similar to what happens at the bottom of our oceans, which could supply enough nutrients to support life. We know that sunlight can’t penetrate Europa’s surface, but life at the bottom of our oceans doesn’t receive sunlight either.

Venting Oceans?

NASA image of Europa possibly venting waterIn 2013, NASA announced that Europa might be actively venting water into space. Because Jupiter’s magnetic field is disrupted around Europa, a special magnetic field may be created by a deep layer of fluid below it’s surface… a global ocean of salt water over 10 times deeper than our oceans.

Future Missions~

NASA image of a fly by of EuropaAlthough several missions have already completed “fly bys” of Europa, future missions will try and provide evidence of a global sized ocean. The most likely mission is now in the planning stages… the “Europa Clipper”, scheduled to launch in the mid 2020’s.

What you can see~

If you go to a star party or astronomy outreach event, seeing the rings of Saturn, the Moon, or the moons of Jupiter for the first time through a telescope is unforgettable. The Saint John Astronomy Club hosts several events throughout the year. Many of these events are at Rockwood Park and Irving Nature Park–see our Upcoming Events page.

RASC New Brunswick, the provincial branch of the Royal Astronomical Society of Canada, also hosts five star parties within the Province, four of which are at designated Dark Sky Preserves. For an overview and upcoming dates see our Star Parties of New Brunswick page.


See also~

NASA link to Jupiter
NASA Galileo Mission
NASA Juno mission to Jupiter

More from Astronomy by the Bay~

Learning the Night Sky
Star Hopping
Favourite Binocular Targets
“Sign Posts” for Navigating the Night Sky [pdf]

Overview~ Astronomy by the Bay

Favourite Binocular Targets

~by Chris Curwin, Astronomy by the Bay

You don’t need a huge telescope to enjoy the night sky…A pair of binoculars is great , and in some cases, actually preferred to a telescope due to their wide field of view. Here are 5 of my favourite binocular targets.. I hope you can grab a pair of binoculars and enjoy them too. The pictures have more info:)

My Favourite Binocular Targets~

Photograph of the Moon showing the terminator line and craters.
The moon is always beautiful through binoculars… and sometimes we even get to view a special event like the partial penumbral lunar eclipse [photo courtesy Paul Owen] that happened in February 2017 :). In that case, the view was more spectacular with the naked eye or through binoculars than with a telescope! Glance along the terminator line during a waxing crescent or quarter moon phase and you’ll see what I mean.

Two photographs showing Messier 45, or the Pleaides and its location in the Constellation Taurus, one of everyone's favourite binocular targetsMessier 45, or the Pleaides, is always an excellent target in binoculars and actually reveals a much better view than through a telescope in my opinion. Look for the Pleiades in Taurus.. the three stars in Orion’s belt point to the star Aldebaran and then on to the Pleiades cluster. (Illustration courtesy earthsky.org, photo courtesy Saint John Astronomy Club member Paul Owen). The Pleaides is one of everyone’s favourite binocular targets.

Photograph of the winter sky Milky Way, as seen from Saints Rest Beach, Saint John, New Brunswick.
The Milky Way can reveal so much… beautiful clusters, colourful double stars and so much more. And you don’t have to wait until summer…There is a “Winter Milky Way” that is also incredible through binoculars. (Photo taken at Saints Rest beach by Saint John Astronomy Club member Mike Powell)

Two photographs of the constellation Orion in the winter sky, showing location and image itself.
The constellation of Orion,  rising early in the eastern winter sky, features many targets… one of my favourites being the Orion Nebula, known as M42.  In the illustration here it is in the area of Orion’s sword, a famous stellar nursery 🙂  Illustration courtesy earthsky.org.

Photograph showing the locations of Jupiter and Saturn in the early winter sky from Saint John, New Brunswick
If you are an early riser (well, not that early, really) you can catch a view of Jupiter and its moons through binoculars… and give Saturn a chance as well. You may not see “glorious rings” but you will see them. This is the sky from Saint John, NB at 630am in early February (illustration from the free program Stellarium).

Photograph of Jupiter and its Moons through binoculars.
The view of Jupiter and it’s Galilean moons .. You can see all of them through binoculars. You can watch day after day as they change positions as they orbit the giant planet.


Questions?  You can contact me on Facebook at Astronomy by the Bay or send me an email.  Thanks.

More from Astronomy by the Bay~

Learning the Night Sky
Star Hopping
“Sign Posts” for Navigating the Night Sky
Europa

Astronomy by the Bay (web)
Astronomy by the Bay (Facebook)


 

Star Hopping

~by Chris Curwin, Astronomy by the Bay

“Star Hopping”…using familiar patterns to help you find unfamiliar objects in the night sky, is a great method used by most amateur astronomers like me. You don’t need a telescope… a pair of binoculars or your eyes will be just fine. Check the photos for some familiar patterns and some easy “new” targets. 🙂 (All illustrations courtesy earthsky.org).

Star Hopping– An Easy Way to Learn the Night Sky

 Photograph of the Big Dipper pointing to Polaris.
The “Big Dipper”… perhaps the most familiar pattern of stars in the night sky, and the stars Merak and Dubhe in the pot, which point to Polaris, our North Star… and the first star in the handle of the asterism known as the Little Dipper. This picture shows star hopping from Dubhe to Polaris.

Photograph of Cassiopeia, Polaris, and Ursa Major
Ursa Major (containing the Big Dipper asterism) also allows us to find the constellation of Cassiopeia. Follow the “pointer stars” in the Big Dipper to find Polaris, and then star hop on to Cassiopeia.

Photograph of West, Winter Evening Sky showing Constellation Andromeda and Great Square of Pegasus
The Great Square of Pegasus, now high in the west on winter evenings. Start from the star on the top left of the square, star hop two stars to the left to the star Mirach, then above Mirach to the star Mu, and then the same distance again above Mu to the Andromeda Galaxy.

Photograph of the Southern Winter Sky late at night showing Constellation Orion while Star Hopping from Sirius to Aldebaran
The belt in the Orion constellation is also another great sign post… with the three stars pointing down, star hop going in a straight line to the left to the bright star Sirius, then reverse direction upward through Orion’s Belt and hop to the right to the red supergiant Aldebaran in Taurus.


Questions?  You can contact me on Facebook at Astronomy by the Bay or send me an email.  Thanks.

More from Astronomy by the Bay~

Learning the Night Sky
Favourite Binocular Targets
“Sign Posts” for Navigating the Night Sky

Astronomy by the Bay (web)
Astronomy by the Bay (Facebook)


 

Learning the Night Sky

~by Chris Curwin, Astronomy by the Bay

Learning the night sky can be a very rewarding experience… and today more than ever, we have many tools to guide us at our fingertips. Astronomy is an outdoor hobby… go out into the night and learn the patterns overhead. Looking up and saying “That’s Polaris!” or “There’s Venus!” can provide a sense of pleasure, and maybe even help you understand a bit more about our universe and our unique role in it’s story.

Learning the Night Sky the Easy Way~

A printable star chart showing constellations to assist in navigating the night sky.A typical, printable star chart can be a great tool under the night time sky. This one is available for download from the website heavens-above.com . The chart can be configured for any date and time. This is tonight’s sky from Saint John around 8pm. Most astronomy magazines also contain star charts.

A photograph showing the constellation Orion in the night winter sky
Look high in the south this evening to find Orion. It’s easily distinguishable pattern remains in the night sky most of the night. Try and see the colour difference between the red supergiant Betlegeuse at the top left and bright blue white supergiant Rigel, bottom right… as well as the Orion Nebula, below the three stars of the belt.

Photo image of the free software program and app Stellarium which assists in navigating and learning the night sky.
Free programs like this one, Stellarium, offer a wealth of information about the night sky. Once configured to your location, you can look up any sky any day of the week. It has many wonderful features and is available for download at www.stellarium.org. Many people consider it the easiest program for learning the night sky.

Logo of the Heavens Above website that provides information on astronomy and navigating the night sky.
An excellent app for tablet or phone is this one, offered at Google Play Store for free. it follows the pattern used on their website… www.heavens-above.com. and will reveal a huge amount of information on the night sky, including the next pass of the space station, satellites, comets and much more. This is only one of many free apps at our fingertips.


Questions?  You can contact me on Facebook at Astronomy by the Bay or send me an email.  Thanks.

More from Astronomy by the Bay~

Star Hopping
Favourite Binocular Targets
“Sign Posts” for Navigating the Night Sky
Europa


Astronomy by the Bay (web)
Astronomy by the Bay (Facebook)