Starry Monday at Otterbein

Astronomy Lecture Series-every first Monday of the month-

February 4, 2008

Dr. Uwe Trittmann

Welcome to

Today’s Topics

• Recent Advances in Astronomy –

Part II

• The Night Sky in February

Feedback!

• Please write down suggestions/your interests on the note pads provided

• If you would like to hear from us, please leave your email / address

• To learn more about astronomy and physics at Otterbein, please visit– http://www.otterbein.edu/dept/PHYS/weitkamp.asp

(Obs.)

– http://www.otterbein.edu/dept/PHYS/ (Physics Dept.)

Recent Advances in Astronomy

• Data

• Theory

• Instruments

• Space Flight

• Space probes

Recent Advances in Astronomy:Space flight

• X-price

• Moon-Mars initiative

• New Space Nations:– China

– India

The Moon-Mars Initiative

• NASA website: “The Vision announced by President George W. Bush on Jan. 14, 2004, offers a "building block" strategy of human and robotic missions, beginning with returning the Space Shuttle to flight and completing the International Space Station. It calls for humans to return to the moon by 2020 and eventually explore Mars and beyond.”

                                                                                •http://www.nasa.gov/missions/solarsystem/explore_main.html

X Prize

• Peter Diamandis is the brains behind the X Prize Foundation, an organization intent on spurring innovation in the development of private low-cost space travel through competitions like the aviation prizes of the 1920s and 1930s. The foundation’s $10 million Ansari X Prize was won in October of 2004 by SpaceShipOne. It also recently announced the WTN X Prize, a series of competitions that will cover all areas of science and technology, the categories of which are still being determined. In 1998, he co-founded Space Adventures, a company specializing in space tourism packages for the likes of Dennis Tito and Mark Shuttleworth.

Space Tourism

• Dennis Tito made headlines in 2001 when he became the world’s first space tourist, paying $20 million to Russia for the privilege of visiting the International Space Station for six days. The trip was the fulfillment of a decades-long dream for Tito, who had originally planned to visit Mir before Russia decided to decommission the aging space station. {Space.com}

Spaceship One

• SpaceShipOne won the $10 million Ansari X Prize when it became the first private craft to take a human into space twice in a two week period. The plane was designed by Burt Rutan and built by Rutan’s company, Scaled Composites Inc. SpaceshipOne’s technology has been licensed by Richard Branson's Virgin Galactic, with flights scheduled to begin in 2007. Rutan is an advocate of space travel “for the rest of us,” and envisions a future in which people will have personal flight vehicles.

• {Space.com}

Spaceship 2

• Test flights this year?

• $200,000 to get to outer space

Orion Spacecraft

• “Apollo on steroids”• Space shuttles schedule to retire by 2010

Orion orbits the Moon

Lunar Ascent

Recent Advances in Astronomy: Theory

• Redefinition of “planets”

• Dark Matter and Dark energy candidates

Pluto’s Demotion

• Since August 2006, Pluto is not a planet anymore, but a “dwarf planet”

• The International Astronomical Union (IAU) voted on a new definition of the term “planet” at its triennial meeting in Prague

• There is hope: lots of astronomers are not happy with the new definition, and could vote to change it in 3 years …

Why is Pluto not a planet anymore? – The Definitions

(1) A "planet" is a celestial body that: – (a) is in orbit around the Sun, – (b) has sufficient mass for its self-gravity to overcome rigid body forces

so that it assumes a hydrostatic equilibrium (nearly round) shape, and – (c) has cleared the neighbourhood around its orbit.

(2) A "dwarf planet" is a celestial body that: – (a) is in orbit around the Sun,

(b) has sufficient mass for its self-gravity to overcome rigid body forces so that it assumes a hydrostatic equilibrium (nearly round) shape2,

– (c) has not cleared the neighbourhood around its orbit, and – (d) is not a satellite.

(3) All other objects, except satellites, orbiting the Sun shall be referred to collectively as "Small Solar System Bodies".

Cleaning up the Neighborhood

• Small objects are forced out of the inner Solar System by gravitational pull of bigger planets

• Small planetesimals collide and form planets

-- or are thrown out!

Why should we change the definitions?

• There were no clear definitions• New data / new discoveries

– Many new trans-Neptunian objects found

– Many new exo-solar planets discovered

It’s the way of science: we build our view of the world based on observations; if it is more convenient we modify our theories, terms, etc. to better represent the world around us.

Quaoar started it

• 2002 Quaoar Discovered

• Quaoar is a frozen world located in what is known as the Kuiper Belt

• At 800 miles in diameter Quaoar is the largest object found in our solar system since the planet Pluto was discovered in 1930.

Soon more followed …

The candidates size-wise: Eris, Pluto, Ceres (and Earth)

Two types of planets

Is the demotion outrageous? – Not unprecendented!

• History of our view of the solar system– Pre-1450 AD: Earth in center (not a planet!), 7

planets (including Sun & Moon!)– Copernicus: Sun and 6 planets– W. Herschel (1781): Sun and 6 planets (add Uranus)– Piazzi (1801): Sun and 7 planets (add Ceres)– A few years later: Sun and 11 planets (add 3 more

asteroids: Pallas, Juno, Vesta)– 1846: a dozen planets (add Neptune)

This just in:

Mercury’s far side

• Until last month, we only knew how 45% of Mercury’s surface looks like Mercurians?

Unique Mercury: double-walled craters

MESSENGER flies through Mercury’s Magnetosphere

Recent Advances in Astronomy: Instruments

• Telescopes – Adaptive Optics– Segmented mirrors– Twin and multiple telescopes

• Amateur Telescopes– Goto technology

• Detectors– CCDs– digital cameras– Particle detectors

Largest Operational Telescopes • 10.4m Gran Telescopio Canarias La Palma, Canary Islands, Spain

– 28 46 N; 17 53 W, 2400 m, Observatorio del Roque de los Muchachos; segmented mirror based on Keck

• 10.0m KeckMauna Kea, Hawaii, – 19 50 N; 155 28 W, 4123 m, mirror composed of 36 segments

• 10m SALTSouth African Astronomical Observatory– 32 23 S; 20 49 E; 1759 m, based on the HET design

• 9.2m Hobby-EberlyMt. Fowlkes, Texas– 30 40 N; 104 1 W, 2072 m, very inexpensive: spherical segmented mirror; fixed

elevation; spectroscopy only• 8.4m Large Binocular TelescopeMt. Graham, Arizona

– 32 42 N; 109 53 W, 3170 m, eventually will have a pair of 8.4-m mirrors giving the light gathering of an 11.8m and the resolution of a 23-m8.3

• 8.4m Subaru, Mauna Kea, Hawaii– 19 50 N; 155 28 W, 4100 Mnaoj

• 8.2m AntuCerro Paranal, Chile– 24 38 S; 70 24 W, 2635m now operate independently in the future will be units of

Very Large TelescopeKueyenMelipalYepun

Telescopes under construction

• 21.4m(7x8.4m)Giant Magellan TelescopeChile,– six off-axis segments plus one central segment form

one optical surface

• 16.4m (4x8.2m)Very Large TelescopeCerro Paranal, Chileall four units now operational; will be combined as an interferometer

• 14.6m (2x10m)Keck InterferometerMauna Kea, HawaiiKeck I and II

• 8m LSSTCerro Pachon, Chileaka Dark Matter Telescope; a fast wide field survey scope

Telescopes of the Future

• 100m OWL OverWhelmingly Large Telescope

• 50m Euro50 

• 42m E-ELT European Extremely Large Telescope

New Telescope Design

Many small mirrors instead of one big one

Adaptive Optics

• Adaptive optics is a technology to improve the performance of optical systems by reducing the effects of rapidly changing optical distortion. It is commonly used on astronomical telescopes to remove the effects of atmospheric distortion, or astronomical seeing. Adaptive optics works by measuring the distortion and rapidly compensating for it either using deformable mirrors or material with variable refractive properties. (Wikipedia)

Adaptive Optics

Lick Observatory laser guide star

Uranus w/o & w AO

The Night Sky in February

• Long nights, getting shorter!

• Winter constellations still high up: Cassiopeia, Pegasus, Perseus, Andromeda, Pisces

lots of open star clusters!

• Mars is visible most of the night, Saturn late at night

Moon Phases• Today (Waning Crescent)

• 2 / 6 (New Moon)

• 2 / 13 (First Quarter Moon)

• 2 / 20 (Full Moon)

• 2 / 28 (Last Quarter Moon)

Today at

Noon

• Sun at meridian, i.e. exactly south

10 PM

Typical observing hour, early February

Saturn

• Mars

Star Maps

Celestial North Pole – everything turns around this point

Zenith – the point right above you & the middle of the map

40º

90º

Due North

• Big Dipper points to the north pole

South-West

Perseus,

Auriga & Taurus

with Plejades and the Double Cluster

South

• Orion• Canis

Major & Minor

• Beautiful open star clusters

• Orion Nebula M42

South-East

• Gemini• Cancer• M44

Beehive (open star cluster)

• Mars

East

• Spring constellations:– Leo– Hydra

• M44 Beehive (open star cluster)

• Saturn

Deep South

• Lepus• Columba• Puppis (part

of the former Argo)

Horizon in Germany (50º lat.)

Mark your Calendars!

• Next Starry Monday: March 3, 2008, 7 pm (this is a

Monday )

• Observing at Prairie Oaks Metro Park: – Friday, February 15, 6:30 pm

• Web pages:– http://www.otterbein.edu/dept/PHYS/weitkamp.asp

(Obs.)– http://www.otterbein.edu/dept/PHYS/ (Physics Dept.)

Mark your Calendars II

• Physics Coffee is every Monday, 3:00 pm

• Open to the public, everyone welcome!

• Location: across the hall, Science 244

• Free coffee, cookies, etc.