Welcome to the WDAS monthly newsletter for April 2017: a digest of the month's latest contributions to our website.  Below you'll find Society News, Sky Notes and In-Focus articles printed in full.  There's also future events, and trailers for other articles which appear in full on the website - just a click away!

On the website you'll also be able to comment on articles, and if you'd like to play an editorial role in creating new content, just let us know!

Society News

Well we are going to be busy late March and into April. 

As you know we have been invited to another ‘Star Night’ hosted by Eskdale School.  This year’s event will take place on Wednesday 22nd of March, starting from 19:00h.  The York University people will be on hand with the inflatable planetarium, and there will be food, soup, cakes, drinks etc available.

On March 28th we have been invited to visit the Whitby Scouts at the Scout hut on Spring Vale.  (Or possibly at Boggle Hole: it's a bit uncertain at the moment - contact Mark to make sure of the latest!)  This is to prepare them for their astronomy badges.  18:15pm.

After been contacted by Elizabeth Labelle, Assistant Head Teacher (Phase III) of Ayresome Primary School & Lego Innovation Studio.  We shall be hosting an event for visiting pupils up at the Whitby Youth Hostel on April 12th.  You may recall we did a similar event last year.  The start time is around 20:30pm.

A new venue now, as we have been asked by Andy Martin, managing director of Northcliffe and Seaview Holiday parks, High Hawsker as to whether we can host a star party event there.  We can, and it is Good Friday – April 14th from 20:30pm.

It would not surprise me if further visits were also forthcoming, but for the moment my crystal ball has gone cloudy.  Let us hope that it’s the only cloud we encounter.

All being well Paul is set to return to Whitby in May.  The venue will be the college main hall (Whitby college as was) May 9th is the date ‘inked in’ and we will be looking to start around 19:30pm.  No definite topic as yet, although Paul has suggested an updated talk on Voyager, to coincide with its 40th anniversary since launch.

It's been a big news week for space, so let's have a round-up in the Newsletter.

Seven Earth-sized Planets around a Supercool Dwarf Star

It’s not often that astronomers find Earth-like planets around other stars. There are a lot of reasons for that. But last spring, a team of researchers announced that they’d found three new Earth-sized, rocky planets with temperatures moderate enough for liquid water, and therefore life as we know it to survive upon. And all those planets are orbiting the same star, which is only 39 light years away!

This week, the group made another big announcement: they found four more planets orbiting that same star. And three of the new planets they found are also Earth-sized, rocky, and at the right temperature for life to survive. They published their findings in the journal Nature.

This is the solar system you want to go to. You could have so many planets! The planets’ parent star is named TRAPPIST-1, and it’s amazingly cool.  In fact, you could call it "ultra cool".  Because that is how it is classified: it’s an ultracool dwarf star. Ultracool dwarfs aren’t much bigger than Jupiter, and they’re just barely hot enough to convert hydrogen into helium, which is how they produce the energy that keeps them going.

Last spring was the first time we’d found planets around an ultracool dwarf, and now we have even more to add to the list, just around this one star. The team found the planets using a common method called transit photometry. When a planet passes in front of its star, it blocks a little of the star’s light, and astronomers can use those measurements to detect planets and figure out some basic information about them. After the first three planets were found around TRAPPIST-1, the team used telescopes on the ground and NASA’s Spitzer Space Telescope to find the remaining four.

Size Comparison: Trappist-1 system vs Jupiter system vs Inner Solar System
Image credit: ESO/O. Furtak

Right now, we don’t know much about the planets besides their size, their density, and that they could be habitable, but we hope to learn a lot more in the coming years, especially with the launch of the James Webb Space Telescope. JWST, which is scheduled to launch next year, will be able to study the atmosphere of these distant planets, which will tell us more about their climate and if there could be liquid water on the surface.

Of course, finding planets where life might be able to survive doesn’t mean they actually harbour life. But with each new discovery, we’re learning that life-friendly environments are much more common in the universe than we once thought. And that includes water within our own solar system.

Organic Molecules found on Ceres and possibiliy of an Underwater Ocean

Ernutet Crater on Ceres: areas
coloured red rich in organics.
Image: NASA/JPL-Caltech/etc

Back in 2015, NASA’s Dawn spacecraft arrived at Ceres, a dwarf planet that’s the largest object in the asteroid belt between Mars and Jupiter. And last week, in a report published in the journal Science, Dawn researchers announced they’d found organic molecules, aka the building blocks of life, on Ceres’ surface.

Organic molecules are carbon containing molecules, which is the foundation for life as we know it. Dawn’s instruments weren’t able to detect exactly what kind of molecules were on the surface, but they’re probably tar-like molecules like kerite and asphaltite.

The probe found large concentrations of the molecules in two different craters - a total of 1400 square kilometres. It’s also possible that Ceres once had an ocean under its surface, though we don’t know if it still does. And it could have some internal heat left over from when it formed.

Combining organic molecules, liquid water, and heat is a pretty good recipe for life - so there’s a possibility that primitive life, like tiny microbes, could have developed on Ceres. It’s still important to remember that all we have at this point is evidence that Ceres has some of the ingredients for life, not that there actually are or ever were living things there. But with about four months left in Dawn’s mission, hopefully we’ll be learning a lot more about that crazy, unusual world.

SpaceX: Manned round-Moon mission announced

SpaceX Dragon to carry comme-
cial passengers beyond the Moon
and back in 2018.  Image: SpaceX

And back here on Earth, it's been a big week for SpaceX.  We discussed SpaceX in Andi's talk on terraforming Mars in February's Meeting, because SpaceX hopes to start taking paying passengers to start a colony on Mars within the next 10 years.  This week SpaceX got two well-healed and paying passengers fly them around and beyond The Moon.  It will be the first time anyone has been outside near-earth orbit since the end of the Moon missions approaching half a century ago.

And it's a kind of testament to Moon missions past and planned, that this week SpaceX launched their first rocket from Pad 39A at Kennedy Space Centre.  Pad 39A is where some of the most important human spaceflight missions began, from Apollo 11 to the last space shuttle flight six years ago. One day, SpaceX hopes to launch the first human mission to Mars from that pad, so the fact that their first launch from 39A was a success is a good start to the next chapter of the launch pad’s story.

Not only did the capsule make it safely into space, but the rocket’s booster also had a picture-perfect landing back on the ground, meaning it can be reused for another mission. The experiments on board represent work from 800 scientists around the world, including projects about things like how wounds heal and how bacteria and stem cells grows in space. The capsule also included instruments, like SAGE-III, which will monitor the Earth looking for atmospheric ozone, and Raven, which will collect data to help future spacecraft dock automatically.

So between finding new Earth-like planets, looking for evidence of life on Ceres, announcing a manned trip round The Moon and launching lots of new experiments, it’s been a big week for space exploration.


The video and most of the material for this article was put together by YouTube channel "SciShow Space". You can support their work creating videos that help to teach the world about astronomy by sponsoring a dollar or two per month via their Patreon page.

I don’t believe it!  The Eskdale ‘Star night’ (Wednesday 22nd) unfortunately coincided with the only bad weather night of the week so our planned outdoor observations were quite out of the question.  No scopes then, but with a new looking inflatable planetarium brought over and manned by York University boffins, who needed clear skies.  All we needed was somewhere to use for the scale solar sytem(s).  An ideal location was at hand – the main school corridor, which at nearly 60 mtrs long was tailormade for our demo.

I say system(s) because two scale systems were laid out over the floor tiles; the Trappist1 system – recently highlighted in the media due to the number of ‘habitable zone planets’ detected, as well as our own system.  At less than half a metre, the Trappist system really didn’t stretch our legs along the corridor, but it did bring home just how ‘intimate’ this seven planet system is huddled around its red dwarf sun.  Our own system did though task the legs of participating school pupils and parents, the narrow confines seemingly focusing the mind on the distances of the outer planets.

Perhaps not the evening we were hoping for, but feedback post event was very positive, stimulating the old brain cells in young and old alike.  Thanks to both ‘Andies’ for their help, either making the Trappist system or assistance on the night.

Just to reminder that we shall be hosting a star party event for visiting pupils from Ayresome Primary School & Lego Innovation Studio up at the Whitby Youth Hostel on April 12thElizabeth Labelle; assistant Head Teacher was impressed with the pupil response and feedback after last year’s inaugural event, and has contacted the society with regards to host another one this year.  The start time is around 20:30h at the WHA on the east cliff.

Cosmology Corner

 

Edwin HubbleIt all started in 1924, when Edwin Hubble proved galaxies are very distant objects, each containing millions or billions of stars, bound together by gravity.  Within a few years, he set up a system to classify these galaxies by shape; a system which is still pretty much the system we use today.

Elliptical galaxy classificationEliptical galaxies

  • Elipticals are marked with the letter E, sub-divided 0-7, where 0 is completely round and 7 is very elongated and flattened.
  • The contain many old stars with very little dust between them.  As stars form from dust, that kind of makes them dying galaxies without the raw ingredients to form many new stars.

Spiral galaxy classificationsSpiral Galaxies

  • There are Regular spirals (S) and barred spirals (SB).  About 2/3 of spiral galaxies have a bar, probably including our own Milky Way.  Spiral galaxies are sub-divided A-C where A has spirals tightly wound around the central bulge and in C the spirals are very loose.
  • They have a mixture of old and new stars, which are particularly created in their spiral arms.

Irregular galaxiesIrregular galaxies

  • Irregulars have a disk around a central bulge, but no obvious dust lanes.  The have no sub-divisions.
  • They often have many bright young stars.  Galaxies can change their shape over time through interactions, collisions and mergers.  These interactions stimulate massive star formation.  If you're thinking that irregular galaxies have been messed-up and shaken-up by this kind of interaction, you're on the right track.

Galaxies also come in a range of sizes

  • The Milky Way is a large galaxy (although there are many both larger and smaller). 
  • There are also Dwarf galaxies, like the near-by Small and Large Magellanic Clouds.  Astronomers think that the total mass of all Dwarf galaxies exceeds the mass of the Large galaxies.

Changes to Hubble's galaxy classifcation system consider brightness, and whether arms spiral outward from a ring of stars.  These changes help astronomers to understand more about their birth and eventual death.


The video and material for this article was made by UK Astrophysicist Sebastian Pines, creator of the 'Astronomic' YouTube channel.  You can support Seb's work creating videos that help to teach the world about astronomy by sponsoring a dollar or two per month via his Patreon page.

Sky Notes

In this month's Sky Notes:

Planetary Skylights

Mercury remains on view low in the evening twilight sky until the second week of April.  Look for the elusive planet across in the west approximately 45 minutes after sunset.  On the 1st Mercury reaches greatest eastern elongation from the sun (greatest separation in the sky) but thereafter rapidly falls back toward the horizon, fading as it does so and is lost to view after the 12th.

Mars is also visible low in the west, upper left of Mercury (or mercury lower right of Mars) The red planet is slowly (very slowly) losing ground in the bright twilight, but will still be visible at the end of the month.  On the 10th Mars lies less than 3 degrees upper right of the dwarf planet Ceres, which should be visible in a pair of binoculars.  From mid month Mars moves up (seemingly) between the star clusters of the Pleiades and the Hyades, both in Taurus.  A crescent moon joins them on the 28th making for a pleasing spectacle to the naked eye.

10-Apr-2017, 21:15h:
Mars and Ceres
Click for full-sized image
28-Apr-2017, 21:45h:
(looking South):
Mars and Moon
Click for full-sized image

Mighty Jupiter takes centre stage in the April night sky coming to opposition on the 7th when it resides due south at midnight.  Look for the beacon of Jupiter low down in the south east as twilight begins to fall.  Observing Jupiter is a must for anyone with a telescope; even binoculars will reveal the Galilean moons.  Note the dark banding across the disk, and if visible the great red spot, which will appear as pale oval hollow on the southern dark equatorial belt.  A modest telescope should reveal it, however as Jupiter rotates in less than ten hours, the GRT is not always orientated in our direction.  Incidentally the star below Jupiter is Spica – chief star in Virgo.  A waning moon resides close by on the 10th.

08-Apr-2017, 21:30h:
Moon and Jupiter
Click for full-sized image
07-Apr-2017: Jupiter with
Moons at Opposition
Click for full-sized image

Saturn rises in early morning hours and is best viewed telescopically shortly before dawn (around an hour).  Saturn resides to the left of a bright red star – Antares, chief star of Scorpius.  Look on the 16th when a waning crescent moon lies upper right of Saturn.

Finally, at the end of April Venus emerges into the dawn sky around 05:00h very low to the east horizon.

Meteor Showers

The Lyrid meteor shower peaks during the day of April 22nd , so the night of 21/22 and 22/23rd should yield some visible shooting stars, especially as the moon will be out of the way.  The hourly rate exceeds 25, however observed

rates will at best be half this.  As with all meteor showers the early morning hours offer the best returns.

A number of lesser meteor showers occur during April.  The Virginids and alpha Scorpiids each have zenith hourly rates (ZHR) of around half a dozen, equating to ‘normal’ sporadic meteor activity levels.  The Virginids peak on April 7/8th, which is a ‘no moon’ window, therefore increased sightings of Virginids during the early morning hours is quite likely.  The Scorpiids peak on the 27th and will be hampered a little by a waning moon in the early morning hours.

Comet 41P Tuttle-Giacobini-Kresák

Yes I know, yet another mouthful, but you may call it Comet 41P or even Comet TGK, and hopefully it should be visible from the last week of March and well into April.  At its closest on April 5th, the comet will be moving a huge two degrees a day (that’s the width of four Full Moons!) as seen from the Earth passing through the celestial dragon of Draco.

Orbiting the Sun once every 5.4 years, this is the 29th perihelion return of the comet since its discovery in 1858.  The comet’s orbit takes it out to near the orbit of Jupiter with perihelion just 0.13 AU outside the orbit of the Earth.  The comet’s passage in 2017 is about as close as it gets to Earth, indeed it is the closest approach in our lifetime.  Currently around +9th magnitude, the comet should flirt with naked eye visibility of (magnitude +6) in early April.  Comet 41P is also worth watching, as it’s known for periodic outbursts, reaching mag +3.9 in 1973.

However please remember comets should come with a observational health warning –so to speak- ;ie they hardly ever do what they are supposed to do.  So if you are going to track 41P down, pick a dark window night, have patience and use a star chart (actually it can be more fun than it sounds) Use binoculars, they will reveal the comet easily, before trying to spot it with the naked eye – if possible!  Below are listed some highlights.

Tracking Comet 41P Tuttle-Giacobini-Kresák

April 2nd: Passes near the 3.6 magnitude star Thuban (Alpha Draconis)
April 5th: Passes just 0.15 AU (23.2 million kilometers) from the Earth at 13:30 UT.  April 11th: reaches perihelion at 1.05 AU (162.7 million kilometers) from the Sun.
April 18th: passes the 2.7 magnitude star Rastaban (Beta Draconis)

April 2017 Sky Charts

Click each image to see a full-size Sky Chart:

Looking North
Mid-April - 21:30h

Looking South
Mid-April - 21:30h

Looking East
Mid-April - 21:30h
Looking West
Mid-April - 21:30h
Northern Aspect
Mid-April - 22:00h
Southern Aspect
Mid-April - 22:00h
 
 
   
Morning Looking East
Mid-April - 05:00h
Morning Looking South
Mid-April - 04:30h

 

Additional Image Credits:

  • Planets and Comets where not otherwise mentioned: NASA
  • Sky Charts: Stellarium Software

Events

A public Star Party, weather permitting, near the Captain Cook monument on West Cliff  (setting-up from 20:45h).  Lunar and Planetary observations.

Solar and planetary observations.

Date:
7 July, 2018 - 21:00
Address:
Captain Cook Headland
West Cliff
near YO21 3HA Whitby
United Kingdom
GB

A public Star Party, weather permitting, near the Captain Cook monument on West Cliff  (setting-up from 20:45h).  Lunar and Planetary observations.

Solar and planetary observations.

Date:
21 July, 2018 - 21:00
Address:
Captain Cook Headland
West Cliff
near YO21 3HA Whitby
United Kingdom
GB

A public Star Party, weather permitting, near the Captain Cook monument on West Cliff  (setting-up from 20:45h).  Lunar and Planetary observations.

The highlight of the summer – Mars at opposition and a total lunar eclipse.  Solar, and planetary observations.

Date:
27 July, 2018 - 21:00
Address:
Captain Cook Headland
West Cliff
near YO21 3HA Whitby
United Kingdom
GB