Top 10 Night Sky Objects for Astronomy Beginners

Your first telescope or binocular has just arrived and now you can’t wait to try it out. Trust me, I remember this feeling very well. The universe is calling and it want to be discovered by you. There are so many exciting objects to explore. So, what to aim your telescope at?  I created a list of ten celestial objects that are great for beginners with binoculars or small telescopes. The targets described represent different kinds of objects that exist in the universe. All objects are easy to find, and their size makes them equally suited for refractors, reflectors, catadioptric telescopes or binoculars. With the exception of the last listing, the Dumbbell Nebula (M27), all objects can be observed even with full moon.

Top 10 Objects for Binoculars and Small Telescopes

Top 10 Night Sky Objects for Astronomy Beginners A short version of the Top 10 Night Sky Objects can be download as PDF and printed. It is a one pager and can serve as reference in the field. Links to constellation maps are offered for all stars and deep sky objects. I really recommend beginners using a planisphere; it makes it so much easier finding constellations and objects. There are many good apps availale, but due to the bright screens of smart phones, they will reduce and hinder night vision.  Another alternative is SkyMaps. They offer great monthly two-pagers that shows all visible constellations and provides useful further information about current stargazing objects.  These maps are free and can be downloaded as PDF.

_________________________________________________________________

Moon

MoonThe Moon is an ever fascinating object that can be observed almost throughout the year. Common presumption is that the moon can be seen best at full moon, but this is actually not the case. The best time is when it is a quarter or less. Sunlight comes now from the side and moon features cast long shadows which render the telescope view almost plastic. It is most exciting to observe along moon edges and the Terminator, the line where the dark and illuminated areas come together.

Facts:
The Moon came into existence when a Mars-size planet crashed into the early Earth. Fragments orbited the Earth and coalesced within just several weeks to become the Moon. The dark areas visible today at the moon are called Maria, from Latin “Sea”. They are meteorite craters that flooded with hot lava. Lava layers can be up to 10 km (6.2 miles) thick, higher than Mount Everest. Diameter: 3 476 km (27% of Earth)
Distance to Earth: 384 000 km (199,000 miles)
Mass: 7.350 x 10E19 tons (1.2% of Earth)
Density: 3.341 g/cm3 (61% of Earth)

Back to table

_________________________________________________________________

Jupiter

Jupiter is the fifth and largest planet in our solar system. It is a gas giant which is primarily composed of hydrogen and helium (very similar to our sun). Jupiter may also have a rocky core of heavier elements.

Jupiter is the largest planet in our solar system. It is a very bright and exciting object to observe. Four moons can be seen even with small telescopes or binoculars. If the conditions are good some cloud bands are also visible, and with larger telescopes it might be possible to see some cloud details and the great red spot.

TIP: It is fun to draw the position of the moons and follow them over a period of time.

Click here for more information about the position of planets.

Facts:
Jupiter is a gas giant with over 100 moons. The four largest are Io, Europe, Ganymede, Callisto. They are also called the Galilean moons. When Galileo saw the movement of the moons he could no longer accept a geocentric model of the universe. Diameter: 142 980 km (11.2 x Earth)
Mass: 1.899 x 10E24 tons (318 x Earth)
Density: 1.32 g/cm3 (24% of Earth)
Distance from Sun: 4.95 AU

Back to table

_________________________________________________________________

Saturn

Saturn, Image credit: Wolf DammSaturn is probably the most enigmatic of all planets. Its rings have given awe to many people who saw it the first time. Since Saturn is double as far from the Sun than Jupiter, it receives only a quarter of the light. While it has almost the size of Jupiter, Saturn’s larger distance results in a smaller, fainter view in the eyepiece. We tend trying to compensate by increasing magnification, but this multiplies air layer disturbances as well. Unless seeing conditions are perfect, a good compromise is a magnification between 100 and 150.

With a very small telescope or under not so good seeing conditions, Saturn’s rings might just be seen as “ears”.  In fact, this is what Galileo saw when he first looked at Saturn with his telescope. He concluded that these “ears” must be two close moons on either side of Saturn, but two years later the “moons” were gone, and again two years later the “moons” re-appeared. We know today, that the “disappearance” was caused by looking at the ring edge on but it was very confusing for Galileo at that time.

Click here for more information about the position of planets.

Facts:
Saturn is a gas giant, and has over 62 moons, with Titan and Rhea as the largest ones. Saturn has a very low density. In fact, if we could build a bathtub large enough to hold Saturn, it would float on the surface. Diameter: 123 000 km (9.4 x Earth)
Mass: 0.569 x 10E24 tons (95 x Earth)
Density: 0.67 g/cm3 (24% of Earth)
Distance from Sun: 9.54 AU

Back to table

_________________________________________________________________

Mizar & Alcor

The Big Dipper is probably the best known asterism for stargazers in the Northern hemisphere. Big Dipper consists of seven stars and belongs to the constellation Ursa Major, or Great Bear. It is easy to find and its serves as guidepost to Polaris. Find the brightest two stars at the outer bowl edge, Dubhe and Merak. Take 5 times their distance and you reach Polaris, the Northern Star.

Mizar & Alcor
Mizar & Alcor (click on image for larger scale)

Big Dipper holds some surprises that are revealed at closer observation. Point your telescope at the handle bend and what you see are not one but two stars. The brighter one is Mizar, the dimmer star is Alcor. They are also known as “Horse and Rider”. People with good eyesight can distinguish these two stars with bare eyes. If the seeing conditions are good, choose high magnification and take a closer look at Mizar. You will see that Mizar itself has another close companion star.  The image above shows an actual photo of Mizar A, his close companion Mizar B and Alcor (click at the image to open a larger scale version).

Click here for a star map of Ursa Major.

Facts:
The Mizar – Alcor system consists of even more stars that are however too faint for small telescopes. Four stars belong to the local Mizar system and the Alcor system consists of two. New research has revealed that both systems are gravitationally linked, making Mizar & Alcor a true 6-star system. Constellation: Ursa Major, UMa
Magnitude (Mizar/Alcor): 2.2 /4.0
Separation: 11.8′
Distance: 83 light years
Mass (Mizar/Alcor): 7.7 /2 x Sun, Diameter: 4.1 / 1.8 x Sun
Luminosity: (Mizar/Alcor): 63 / 13 x Sun

Back to table
_________________________________________________________________

Albireo

In the night sky: late Spring to Fall.

Albireo, HunterAlbireo is the fifth brightest star in the constellation Cygnus (Swan). With naked eye it appears to be single star but a telescope resolves it as double star. Both stars offer a striking color contrast. The brighter star shines in yellow color, the smaller star in blue.

Image credit: Hunter Wilson.

When observing colorful stars, it can be beneficial to do this somewhat out of focus. Since the star disks become larger, colors become more prominent. The reason for this is that a larger number of color receptors in the eyes can collect color information . Play with your focuser and see what works best for you.

Click here for a star map of Cygnus.

Facts:
At this point it is unknown whether the stars are optical doubles or gravitational linked and orbiting each other.The brighter star itself has a very close companion, too close though to be resolved with a telescope. Constellation: Cygnus, CYG
Magnitude: A 3.2, B 5.8
Separation 35″
Distance 390 / 390 light years
Mass: 5 / 3.2 x Sun
Diameter: 16 / 2.7 x Sun
Luminosity: 950 / 120 x Sun

Back to table

_________________________________________________________________

Orion Nebula (M42)

In the night sky: Winter and Spring.

Orion Nebula (M42)The Orion Nebula is part of the constellation Orion. This truly beautiful nebula can be found just below Orion’s belt as a part of Orion’s sword. It is one of the brightest nebulae and is visible to the naked eye.

Because M42 is over an arc minute wide use your lowest magnification to ensure it fits in the field of view. The four stars at its center are called “Trapezium”, they energize and ionize surrounding gasses which leads to this beautiful spectacle.  Due to its brightness, the Trapezium stars draw the observers attention, but when scanning the area around them, you will see many smaller stars and layers of ionized gas.

Click here for a star map of Orion.

Facts:
Orion nebula is the closest region of massive star formation to the Earth. It hosts protoplanetary discs and brown dwarfs. New stars and planets are born there right now. The strong radiation emitted by the Trapezium stars is so powerful that young neighbor stars are pushed into the form of an egg. Constellation: Orion, ORI
Magnitude: 4.0
Size: 65’x60′
Distance 1,344 light Years
Diameter: 24 light Years
Mass: 2,000 x Sun

Back to table

_________________________________________________________________

Andromeda Galaxy (M31)

In the night sky: Summer, Fall and Winter.

Andromeda Galaxy (M31)The Andromeda Galaxy belongs to the constellation Andromeda. It is the farthest object that can be seen with bare eyes. It is so large that it will most certainly exceed the field of your telescope view (binoculars have sufficient viewing angle). Nevertheless it is a fascinating moment taking a peek at another galaxy for the first time. The core of Andromeda is very bright and the surrounding areas can be seen nicely.

There are many ways finding the Andromeda Galaxy in the night sky. My favorite is to extend the most pointy part of the Cassiopeia “W” three times.

Click here for star maps of Andromeda and Cassiopeia.

Facts:
The Andromeda Galaxy is a spiral galaxy has an estimated 1 Trillion stars (Milky Way 200 – 400 Billion). Its center comprises a massive black hole. Andromeda Galaxy and the Milky Way are moving towards each other. They will merge in about 4.5 Billion years. Constellation: Andromeda, AND
Magnitude: 3.44
Distance 2.54 Million light years
Mass: 1- 1.5 x Milky Way galaxy

Back to table

_________________________________________________________________

Hercules  Cluster (M13)

In the night sky: Spring, Summer and Fall.

Herkules Globular Cluster, Image credit: ESA, NASAAs it’s name already reveals, the Hercules Global Cluster lies in the constellation Hercules.  The Globular Cluster is almost as old as the known universe and offers beautiful view even for small telescopes.

Image Credit: ESA, NASA

It is a bit more challenging to find Hercules Globular Cluster. First we have to find “The Keystone”, four stars of the constellation Hercules that build a trapezoid. M13 lies on the line between Eta Herculis and Zeta Herculis. These are the two stars in “The Keystone” at the side of Arcturus. Move a little bit towards Eta on the Eta-Zeta line and you have found this beautiful globular cluster. If you have difficulties to find “The Keystone”, two bright stars, Vega and Arcturus help. Draw a line from Vega to Arcturus, “The Keystone” is located about one third the distance from Vega.

Click here for a star map of Hercules.

Facts
Despite it’s age, Hercules Globular Cluster has not changed its form much. Pressure of star radiation pushing stars apart and gravity force pulling them together, resulting in an equilibrium. The stable conditions were thought to be beneficial for possible forming of life. In 1974 a radio message was sent to the Hercules Cluster with the large Arecibo radio telescope. The digital message included information about man, earth and the solar system. Constellation: Hercules, HER
Magnitude: 5.8
Distance 25,100 light years
Diameter: 168 light years
Mass: 600,000 times Sun
Age: 14 Billion years

Back to table

_________________________________________________________________

Double Cluster (NGC 869 & NGC884)

In the night sky: Fall, Winter, Early Spring.

The Double Cluster (NGC 869 & NGC884), Image credit: Wolf DammIn his classic Field Book of the Stars (1929), William Olcott called the Double Cluster: “One of the finest clusters for a small telescope. The field is simply sown with scintillating stars, and the contrasting colors are very beautiful”. Does this not make anyone thrilled to observe this fine object? What we see are in fact two independent open clusters. They are about 800 light years apart but due to their position in the sky, they fit both in the view of a small telescope.

The Double Cluster belongs to the constellation Perseus. It can be easily found with the help of the constellation Cassiopeia. Just follow the inner leg of the shallow half of the “W” (Cassiopeia Gamma – Delta) about two third of the way to the next bright star, and you will find the Double Cluster.

Click here for star maps of Perseus and Cassiopeia.

Facts:
The Greeks knew about the object as early as 130 BC, but the true nature of it was not discovered not before the telescope was invented.
The radiant of the Perseid meteor shower (Aug 12 & 13) is located in the neighborhood of the Double Cluster (SW).
Constellation: Perseus, PER
Magnitude: 4.2
Distance (NGC 869): 6,800 light years
Distance (NGC 884): 7,600 light years
Age (NGC 869): 5.6 Million years
Age (NGC 884): 3.2 Million years

Back to table

_________________________________________________________________

Dumbbell Nebula (M27)

In the night sky: Fall, Winter, Spring

Dumbbell Nebula (M27), photo credit: Wolf DammWith a magnitude of 7.5 , the Dumbbell Nebula is the faintest object in our Top-10 list. It is however the second largest planetary nebula in the northern sky and can be found relatively easily. The Dumbbell Nebula is located in the constellation Vulpecula, Latin for “Little Fox”. Vulpecula is a very small constellation with faint stars, southwest of Albireo in the constellation Cygnus. My preferred way to find M27 is with the help of the constellation Sagitta, the “Arrow”, just south of it. Its stars are brighter so they are easier to make out. They are shaped like an arrow with feathers (or a triangle  with tip). The Dumbbel Nebula, M27 is pretty exactly north of Sagitta’s tip star, Gamma Saggitae.

Click here for star maps of Vulpecula, Cygnus and Sagitta.

Facts:
M27 is a planetary nebula. This term was coined by early astronomers who thought these nebulae were planets. In fact, they have nothing to do with planets. Planetary nebulae are clouds of material, shed by a star. It glows because it is excited by radiation emitted by a nearby object. Constellation: Vulpecula, VUL
Magnitude: 7.5
Distance 1,360 light years
Diameter: 1.44 light years
Central star
Dia: 0.055 Sun, Mass: 0.56 Sun
Age: only 9800 years

Back to table

The Moons of the Solar System

More Questions Than Answers

Europa Moon of Jupiter
Europa – Moon of Jupiter. Credit NASA

Think of our solar system, and for most of us the first thing to come to mind would be the eight planets orbiting our Sun. But perhaps even more interesting are the moons which orbit the planets. Our Moon seems to be a lifeless body, with hardly any atmosphere and no dynamic activity. But the more data we collect, and the more we learn about its formation, the more fascinating it becomes. The same is true of the moons of the outer gas giants, some of which are comparable in size to the Moon. Little was known about these bodies until we began to send spacecraft armed with a host of sensors in order to analyse them in much greater detail. Each has its own uniquely distinctive characteristics in terms of overall composition, and their widely diverse range of surface features give tantalizing clues to what is going on beneath. The image below shows the size of the Earth’s Moon in relation to other moons and planets in the Solar System.

Moons of the Solar System
Moons of the Solar System / Credit NASA

Galileo and the Beginning of Modern Astronomy

In 1610 Italian astronomer Galileo Galilei discovered the four largest moons of Jupiter; Io, Europa, Ganymede and Callisto. He used a homemade telescope to observe the motion of these bodies, which he first took to be stars. But after a few weeks he realized that they never left the vicinity of Jupiter, and they changed position in relation to each other and the planet. Galileo therefore concluded that they must be planetary bodies in orbit around Jupiter. This discovery, along with his measurements of the phases of Venus, proved that not everything in the Universe revolves around the Earth, and led to conflict with the Catholic Church by refuting the geocentric view of the Solar System. But importantly for science, his work also marked the beginning of modern astronomy.

Jupiter-moons_475px
All that’s required to see the Galilean moons of Jupiter is either a good pair of binoculars or a small telescope. Credit: Jan Sandberg, www.desert-astro.com

The Inner Solar System

Phobos_Deimos_475px
Phobos (left) and Deimos (right), Moons of Mars. Credit NASA

Both Mercury and Venus have no moons at all. One theory for this is that if they ever possessed a moon in the past, it would have eventually been stolen by either the gravitational pull of the Sun or the gravitational pull of the host planet. Then there’s Mars which has two moons, Phobos and Deimos. These are very small bodies, with Phobos having a diameter of 22.2 km and Deimos 12.4 km, so they haven’t got enough mass to enable them to form into the roughly spherical shapes that larger bodies are able to do. The orbital radius of Phobos is just 9,377 km, with an orbital period of 0.32 days. It is being pulled 1.8 m closer to Mars every century, and so will eventually either crash into the planet or break up and form a ring of material around it. Deimos, on the other hand, has an orbital radius of 23,460 km, and is gradually moving in the opposite direction, away from Mars, just like our own Moon is moving away from the Earth. So one day both Deimos and the Moon will cease to be influenced by the pull of their host planets and be set free into space.

The Outer Solar System

Io, moon of Jupiter shown with plume. Credit: NASAIt seems reasonable to assume that the further from the Sun the colder the temperature of the bodies that exist there. At Jupiter, which lies five times further from the Sun than the Earth, the average surface temperature of its moons is -170°C. At Saturn the average surface temperature is -200°C, at Uranus -210°C, and at Neptune -235°C. Before it was possible to closely inspect the moons of the outer planets in any great detail, scientists assumed that, due to these low temperatures, they would be cold, lifeless, inactive bodies. But since Voyager 1, launched in 1977, the Galileo mission, launched in 1989, and Cassini-Huygens in 1997, it has become clear that their theories were very far from the truth. Io for example, the innermost of the four Galilean moons of Jupiter, is the most volcanically active body in the solar system. Whilst having an average surface temperature of -130°C, its volcanoes can reach 1,650°C. It is covered in sulfur due to the hundreds of active volcanoes on its surface, and has lava lakes, floodplains of liquid rock and plumes of sulfur reaching as high as 300km. The above image (credit: NASA) of Io showing an active plume from a volcano. Io’s colorful appearance is due to various materials produced by its volcanism, including silicates, sulfur and sulfur dioxide.

Resonance

The reason for Io’s volcanic activity is due to the orbital resonance of three of the four Galilean moons, meaning that their orbital periods are multiples of each other. Io revolves around Jupiter four times in the same period it takes Europa to revolve twice and Ganymede to revolve once. This regular alignment results in a gravitational pull which has caused their orbital paths around Jupiter to become elliptical. This in turn creates immense tidal forces, causing the physical rock on Io’s surface to rise up and down a hundred meters during the course of each Io day, or about every 42 hours. A huge amount of heat is therefore generated, which is enough to melt a large proportion of Io’s interior and bring about the conditions we have observed on its surface from pictures relayed by Voyager 1 in the late seventies and the Galileo mission in the late 1990’s and early 2000’s. Resonance is common in the solar system, and accounts for the geysers and the jets on Enceladus for example, and the liquid water ocean beneath the surface of Europa.

Cryovolcanism

Image taken by NASA’s Cassini probe of jets of water ice being emitted from the surface of Enceladus. Credit: NASA/JPL/SSI
Image taken by NASA’s Cassini probe of jets of water ice being emitted from the surface of Enceladus. Credit: NASA/JPL/SSI

Volcanism does not only occur on rocky bodies like Io. In March 2006 the Cassini probe observed icy jets being emitted from the south pole of Enceladus, a moon of Saturn. The volcanoes erupting these jets were however not spewing out molten rock. When Cassini flew through the plume of one of these emissions, it detected predominantly salty water-ice, with small amounts of carbon dioxide, ammonia, methane and other hydrocarbons. The contaminants lower the melting temperature of the ice on the crust of Enceladus, allowing the generation of cryomagma, which can be erupted in plumes reaching hundreds of kilometers above its surface. Other icy moons exhibiting cryovolcanism include Ariel and Miranda orbiting Uranus, and Triton, the largest moon of Neptune.

Is There Life in the Solar System?

Mars has traditionally been the place to look for alien life in the solar system, but the icy moons of the outer planets are exciting for scientists to study because their surfaces are comprised of large amounts of water ice. Although solid at the surface, it has been proven that vast amounts of liquid water can exist underneath. The Galileo mission to Jupiter gave evidence that Europa has an ocean of water beneath its icy surface totaling more than all the oceans, rivers and lakes existing on the Earth. And where there’s water there’s the potential for life, at least life as we know it. Tidal distortion has created cracks on the surface of Europa, enabling liquid water to escape to the surface. These could be the places where life is most likely to occur, as sunlight could create the conditions for photosynthesis to take place. Other places with the potential for life are Ganymede, Enceladus and Titan, Saturn’s biggest moon.

Plate tectonics on Europa. Image Credit: NASA
Plate tectonics on Europa. Image Credit: NASA

But life can also be created without the need for sunlight. At the bottom of our oceans on Earth, hydro-thermal vents exist that harbor microbes which, in a process called chemosynthesis, convert chemicals from the vent into usable energy. So why can’t this same process take place elsewhere in the solar system, or elsewhere in the Universe for that matter?

Future Exploration

NASA’s New Horizons spacecraft is one of the latest ongoing missions to explore the solar system. It is on its way to a rendezvous with the newly termed dwarf planet Pluto and its moon Charon, both members of the vast region beyond Neptune known as the Kuiper Belt. Launched in 2006, and moving at almost one million miles per day, it will reach Pluto in summer 2015, armed with much more state of the art sensors than earlier missions. For instance, it will include LORRI, one of the highest resolution telescopes ever sent into space. Scientists believe that the Kuiper Belt contains a totally different class of world than the rest of the Solar System, so to better understand it, we need to understand worlds like Pluto and Charon.
In 2022 the European Space Agency is planning to launch the Jupiter Icy Moons Explorer (JUICE), which will study Ganymede, Europa and Callisto, and their potential for containing life. NASA too is hoping to launch its own mission to Europa in 2022, called the Europa Clipper. It will fly down to within 25km of its surface, and may even include a lander. So the future of space exploration is alive and well, with plenty of exciting encounters to look forward to.

Asteroid Mining (C, S, M Types) – Know Everything About It

Asteroid Itokawa
Near Earth Asteroid Itokawa. A likely candidate for future mining opportunities. Credit JAXA

Look back in history and you will see that the motivation behind huge investments in exploration and transportation has been the need for resources.  The American settlers headed west in their search of gold, oil and timber, and the Europeans headed east along the Silk Road and the spice trade routes.  Now, a company based in Seattle, Washington, plans to head away from Earth and into space in search of the precious resources to be found within the thousands of asteroids existing in orbits relatively close to our planet.

The company, Planetary Resources Inc, founded by Eric Anderson and Peter Diamandis, has attracted a group of investors and advisers including Eric Schmidt and Larry Page of Google, and film director James Cameron.  The ultimate goal is to exploit the valuable resources which asteroids can offer, and the biggest challenge is to achieve this within a budget which makes the whole project cost effective.

Why is asteroid mining such an exciting proposition

How an asteroid could be captured and moved into a more convenient orbit. Credit Planetary Resources

Asteroids contain an abundance of valuable resources including platinum, gold, iron, nickel, rare earth metals and water.  At present around 9,000 known asteroids travelling in an orbit close to Earth’s have been identified, with around 1,000 new ones being discovered each year, all of which as easy to reach as the moon.  And because they are much smaller than the moon the lower gravitational force will mean that landing and taking off will be less of a problem.  Unlike the Earth, heavier metals are distributed evenly throughout an asteroid’s mass rather than closer to the core, and as an added attraction the presence of these materials will often be found in much higher concentrations than on Earth.  For instance, it has been estimated that a one kilometer diameter asteroid could contain about 7,500 tons of platinum, worth more than $150 billion.

Rare Earth metals

Despite their name, rare earth metals are fairly common in the Earth’s crust, but the fact that they are so widely scattered makes them difficult to mine. So finding a viable means of harvesting them from space will potentially be a highly profitable business.  Added to this, around 95% of the world’s supply of rare earth metals presently comes from China, who have decided to cut back on their exports in order to accommodate their own rapidly expanding industrial needs.

Platinum group metals

Platinum group metals do not occur naturally in the Earth’s crust, but are present due to earlier meteorite impacts.  A meteorite is simply a piece of asteroid which has fallen to Earth, so the study of meteorites gives geologists a good idea of the most suitable types of asteroid to choose as candidates for mining.

Which are the most likely candidates?

An artist’s impression of the Asteroid Belt. Credit NASA

The vast majority of asteroids are located in the region of our Solar System between Mars and Jupiter called the Asteroid Belt, or Main Belt.  They range in size from around half a mile across to about 600 miles in diameter, and were created at the birth of the Solar System, 4.6 billion years ago.  To put it into perspective, the total mass of all known asteroids, more than half a million in all, is about 4% that of the moon.  Due to the gravitational influence of Jupiter some have orbits which carry them close to Earth, in which case they are called Near Earth Objects, or Near Earth Asteroids.  And these are the asteroids which Planetary Resources intend to study and ultimately exploit.

How are asteroids classified?

 In broad terms there are three classifications of asteroid based on their composition:

  • C-type, which are the most common, are carbonaceous, and consist of clay and silicate rocks.  They exist furthest from the Sun, and so have been least altered by heat, meaning that they are the most ancient. Due to the fact that some have never even reached temperatures above 50°C, it is estimated they can contain up to 22% water.
  • S-type or silaceous asteroids are made up primarily of stony materials and nickel-iron.  They inhabit the inner Asteroid Belt.
  • M-type, or metallic, are made up mostly of nickel-iron, and are found in the middle region of the Asteroid Belt.

 

2005-YU55, a C-type asteroid. Credit NASA

 

What are the challenges?

 The greatest challenge to Planetary Resources is to build commercially available robotic spacecraft which are at least an order of magnitude cheaper than those currently in use.  Unlike governments, failure can be accepted during the development process, and the goal is to build the crafts in an assembly line fashion in order to drive down costs.  The project will be carried out in stages, with the first phase already underway, and it is hoped that by the middle of next decade mankind will be reaping the benefits of the abundant resources that asteroids have to offer.

 The technology

  • The Arkyd Series 100 – Leo Space Telescope.  Due for launch within the next two years, its job will be to analyse NEOs in order to determine the most likely candidates for future exploitation.  Techniques such as spectroscopy and radar technology will be used to determine properties such as the asteroid’s chemical composition, orbit, rotation, size, shape and metal concentration.  Due to its relatively low cost and its potential usefulness in a vast number of applications, the Leo will be of interest to the scientist and private citizen alike.  The sale of these crafts will therefore enable Planetary Resources to gain revenue in order to achieve its future objectives.
  • The Arkyd Series 200 – Interceptor.  The intention is for this craft to hitch a ride on a geostationary satellite in order to analyse asteroids at more close quarters.  Future advancements in micro-propulsion and imaging techniques will be utilised to enable the craft to get close enough to obtain high resolution data.  Two or more Interceptors working together will ensure that the data is collected as quickly and efficiently as possible.
  • The Arkyd Series 300 – Rendezvous Prospector.  This phase of the project will involve focusing on asteroids much deeper in space.  Laser communication technology will be used  to determine shape, rotation, density, and surface and sub-surface composition.  The Prospector’s capability as a low cost interplanetary spacecraft should also attract customers such as NASA and other scientific establishments.

    Arkyd Series100 – LEO Space Telescope. Credit Planetary Resources

 

Mining

After all the prospecting has taken place, the most exciting phase of the project can then be carried out, the actual mining of the precious resources.  Initially the most important resource available in space will be water.  Apart from being essential to sustain life, it can also be split into hydrogen and oxygen to create fuel to enable spacecraft to travel further into space.  This would allow us to build refuelling stations in order to reach more distant asteroids and aid future manned exploration of the solar system.  For this reason the first targeted asteroids will most likely be C-type.

What methods will be used?

Could this be the future of asteroid mining? Credit Kevin Hand for Popular Science, 2012

The technology needed to carry out the mining process has not yet been developed, but possible methods have been suggested.  A device similar to a snow blower, anchored to the surface, could be used to collect loose rubble by using a spinning blade to fling the material through a chute and into a high-strength bag.  Many of the mining methods will be similar to those used on Earth, and will consist of drilling, blasting, cutting and crushing.  Extraction of individual materials, depending upon their properties, will be achieved by either chemical or physical means.  Water can be extracted by heating the solid material, capturing the vapour and then distilling it; electrolysis of molten silicates would produce oxygen, iron and other alloys; and a method called the Mond process could be used to extract nickel.  As well as being used for creating industrial wealth on Earth, these raw materials could also be used to actually build structures in space.  Dozens of other processes are being considered, and meteorites are the perfect objects to experiment with on Earth.

Within reach!

The idea of landing a robotic craft onto an asteroid in order to extract its precious materials may at first seem the stuff of science fiction.  But the more scientists get to grips with the technology necessary to achieve it, the more likely it is that science fiction will soon become science fact.

Astrophotography – Without a Telescope

Milky Way, Credit: Ralph Clements

By Ralph O. Clements

When I was invited to write about this subject for Astronomysource.com, I must say I was flattered and a bit flabbergasted too, as I do not consider myself an expert on the subject, nor a writer by any means, but just a guy who likes to go out at night and take pictures of the sky. I stumbled into this hobby when my wife brought home an old 4” Meade reflector telescope with a manual equatorial mount from a yard sale that she paid $60 for.

I took that thing out in the country and set it up (completely wrong, I now understand) and as darkness approached, held my point-and-shoot camera up to the eyepiece and took a picture of Venus. Well, now that was very interesting…it was certainly not a very good photo and I have learned it is hard to get a good one of Venus, but I could tell it was not a star, it was not round but had a semi-circular shape. Wow! I took a picture of another planet! That got the gears turning in my head and I just had to do more….I mean who would think I could take a picture of another planet, with a point-n-shoot camera and an old yard sale telescope?

“Camera Only” Images

I do take images with newer telescopes and a decent equatorial mount which I have acquired since. Imaging galaxies and nebulae is an ongoing goal and interest, but I have learned that it is time consuming, tedious and has a fairly steep learning curve. My view of the sky at home is very limited. So for the time it takes to drive out to the country and get all that gear set up and working, I am limited to weekends and then only weekends when the sky is clear. Since clarity of skies does not always happen on Friday or Saturday night, I often image without the telescopes at all. All the tips and advice offered here is just what I have learned and I expect others may have better ways of doing things.

_________________________________________________________________

_________________________________________________________________

Equipment

My research indicated that Canon cameras are preferred for astrophotography and the T1i is what I use for everything. I also have an older Nikon DLSR with two lenses, a 180mm fixed focal length and a 75-300mm zoom, for which I bought a Canon adaptor, but the 18-55mm “kit lens” that came with the Canon is what I use most often.

If you read up on astronomy and astrophotography equipment you will note it is often said that the mount is every bit as important as the telescope. My camera tripod is my mount and I fully agree that a sturdy tripod is a must. I am fortunate to use a tall Berlebach tripod with hardwood legs. The cheap aluminum department store tripods are not stable enough.

Figure 1: Orion at Peaks of Otter, Credit: Ralph Clements

Widefield & Star Trails

Camera only astrophotos with a static tripod fall into these three general categories:

Widefield – Single Shot

These include what would be considered “scenic” or “landscapes” in daytime photography, that is, including some portion of the Earth, as well as constellations and shot of the Moon (See Figure 1). I try to shoot as long as possible without having oblong or streaked stars. A high ISO setting helps with this and I often use 3200 ISO unless it is twilight or too much man made light is around. Figure 1, Orion and the Peaks of Otter, is a 10 second exposure and the stars are a bit oblong but not too bad.

Widefield – Stacked Images

Images that are composed of multiple single exposures, stacked and aligned in the computer to reveal much more of the faint light features than what is visible to the naked eye. Sagittarius (Figure 2) was taken as series of short, 6 second shots and stacked in the computer using Deep Sky Stacker. The exposure time for shot like this can vary depending on the target, its location in the sky and ambient light conditions. I find that targets nearer the poles may allow a little longer exposure than those on or near the celestial equator, which appear to move more due to their location.

Figure 2: Sagittarius, Credit: Ralph Clements

Star Trails Shots

Long Exposures or combined multiple exposures that show the apparent rotation of the stars above the Earth. Of course, the stars just appear to rotate because we are riding on the Earth which is really doing the rotating (Figure 3).

Taking star trails images is fun, easy and I like the look of them. Although a star trails image of say 40 minutes can be done on the “bulb” setting with a single exposure, this requires a remote timer and more importantly, a very, very dark site as the least ambient light will over expose the shot during that time. So I just take a series of 30 second shots and combine them using “Startrails” software, another useful and free program. This software is definitely easy to use and produces good results, although I do not notice much improvement when I use dark frames with it. For noise reduction I use “Noiseware Community Edition” in the final images instead. I recently became aware of another free software to do this, “Starstax”, and will be trying it soon as it offers more features.

On these star trails shots, sometimes it is good to have some moonlight on the subject and I will go out under a quarter to half moon and shoot them. I find a full moon makes it too much like daylight for my taste and if I lower the ISO under a full moon the stars don’t show up much. So depending on the amount of moonlight, artificial light and desire ground detail, I take these star trails shots at ISO setting of 800, 1600 or 3200. Generally, I try to get 40 to 60 minutes total exposure. Less than that and the trails are too short, more than that and chances are airplane will mess it up.

Figure 3: Startrails, Credit: Ralph Clements

Foreground and Framing

I try to pick a good site with some interesting foreground , although “fore-ground” in this case doesn’t mean close to the camera, rather, it means the part of the Earth that is shown.  I try to frame the shots so that the sky covers roughly ¾ of the frame, since the sky is the real subject and the foreground is really just a reference or point of interest.

Focusing

To get crisp focus on the stars and the ground, anything in the image needs to be as far away as your camera’s “infinity” focus distance, which varies with the lens. So I try to take scenes that I would focus to infinity on if I were shooting them in daylight, such as the farm you see in Figure 3.  For all my images I use the camera’s “live view “. This feature lets me zoom in on a bright star, or the moon and focus. If your target is too dim, aim at a brighter one or an artificial light a long way off and focus on it and re-aim at your target. Make sure your camera is not set to “auto-focus”, use “manual”. The Nikon I was using did not have “live view” but I used the same method, only I looked through the view finder at a bright star or light. Sometimes a few test shots were needed to get it right.

Getting Started

As for general advice for other beginners, I offer the following

  • Read your camera’s instructions, particularly the section on manual control.
  • Learn to work your camera’s controls in the dark, the corollary of which is….
  • Don’t be afraid to experiment. I use the trial and error method, with lots of trial and plenty of errors. That’s okay though as I am having fun and try to learn from my mistakes, and I don’t have to buy film for a digital camera, so I don’t mind deleting the ones that didn’t come out.

….just do it! Have fun with it.