SOUDIPAN MAITY

GOOD MORNING EARTHLINGS!

What were the odds of us being gathered in this room today, in this very location, at this very moment, when the Big Bang occurred 13.7 billion years ago?!

Might’ve been a few trillions-to-one chance!

That did happen eventually, didn’t it?

Isn’t this Universe just too damn fascinating?!

WE’VE OFTEN HAD QUESTIONS IN OUR MIND

SUCH AS…

Where does the universe end?

What is deep space? What lies in it?

How far has man gone into space?

How far has a man made spacecraft gone?

How long will it take a spaceship to stepinto the next galaxy?

Do we have the technology to do it?

What’re the odds of us being the only lifeform in an universe that has 100 billiongalaxies each of which consists ofalmost 10 billion solar systems?

AGENDA

What is Deep Space?

Where does the Solar System end?

Modes of Space Exploration

Observation through Space Telescopes

Interplanetary Spaceflight

Interstellar Travel

Our place in the universe

References

WHAT IS DEEP SPACE?

Void that exists between celestial bodies,including the Earth, not completely empty.

Consists of a hard vacuum - a low density ofparticles, predominantly a plasma ofhydrogen and helium as well aselectromagnetic radiation, magnetic fields,neutrinos, dust and cosmic rays.

The Kármán line, at an altitude of 100km (62 miles) above sea level, isconventionally used as the start of outerspace in space treaties and for aerospacerecords keeping.

WHERE DOES THE SOLAR SYSTEM END?

Heliosphere is the bubble-likeregion of space of electricallycharged particles emanatingfrom sun (solar wind)extending beyond Pluto’s orbit.

But, the edge of heliosphereis NOT the same as the edgeof the solar system!

The Oort Cloud is a cloudmade of icy comets believed tobe surrounding the Sun tosomewhere between 50,000 &200,000 AU.

Outer limit of the Oort cloud defines the cosmographical boundary of the Solar System.

The solar system and the Oort cloud(distance in astronomical units)

MODES OF SPACE EXPLORATION

• OBSERVATION THROUGH SPACE TELESCOPES

• INTERPLANETARY SPACEFLIGHT

• INTERSTELLAR TRAVEL

SPACE TELESCOPES

An instrument located in outer space to observe distant planets, galaxies and other astronomical objects.

Avoids many of the problems of ground-based observatories, such as light pollution and distortion of electromagnetic radiation.

Ultraviolet frequencies, X-rays and gamma rays which are blocked by the Earth's atmosphere, can be observed from space.

The first operational space telescopes were the American Orbiting Astronomical Observatory OAO-2 launched in 1968 and the Soviet Orion 1 ultraviolet telescope aboard space station Salyut 1 in 1971.

‘Great Observatories’ Program: Developed by Dr. Charles Pellerin, NASA's former director, Astrophysics, it is an array of four large, powerful space-based astronomical telescopes.

NASA ‘GREAT OBSERVATORIES’ PROGRAM

Telescope Launched Observation Spectrum

Hubble Space Telescope (HST)

1990 (aboardthe Discovery)

Visible, near-ultraviolet& near-infrared

Compton Gamma Ray Observatory (CGRO)

1991 (aboard the Atlantis)

Gamma & Hard X-rays(de-orbited in 2000)

Chandra X-ray Observatory (CXO)

1999 (aboard the Columbia )

Soft X-rays

Spitzer Space Telescope (SST)

2003 (aboard a Delta II rocket)

Infrared

The Hubble Space Telescope (HST) as seen from the departing Space Shuttle Atlantis after a refurbishing mission

HST’s view of the Pillars of Creation, a small region, of the Eagle Nebula 6,500 light-years

away

HST’s view of the Horsehead Nebula 1,500 light years away

A composite image taken by HST of a magnificent spiral galaxy M106lying 23.5 million light-years away, in the constellation Canes Venatici

This is the largest and sharpest image ever taken of the Andromeda galaxy. It is the biggest Hubble image ever released and shows over 100

million stars and thousands of star clusters embedded in a section of the galaxy’s pancake-shaped disc stretching across over 40,000 light-

years.

Visit http://hubblesite.org/ to see more such jaw-dropping images in full resolution, clicked by this HUBBLE DUDE!

CHANDRA X-RAY OBSERVATORY (CXO)

Rosette Nebula located 5,200 light years away as seen by Chandra X-ray observatory

Artist’s impression of Chandra X-ray Observatory (CXO)

SPITZER SPACE TELESCOPE (SST)

Spider Nebula as seen by Spitzer in infrared situated 10,000 light-years away

Artist’s impression of Spitzer Space Telescope (SST)

HOW FAR HAVE WE SEEN IN SPACE?

Universe: 13.7 billion years old!

Light from anything at thatdistance would’ve been travelingtowards us for 13 billion years!

Hubble Ultra-Deep Field(HUDF) is an image of a smallregion of space in theconstellation Fornax, locatedsouthwest of Orion, containingan estimated 10,000 galaxies!

Composited from Hubble SpaceTelescope data over a periodfrom 2003 to 2004.

Hubble Ultra Deep Field Image

INTERPLANETARY SPACEFLIGHT

Travel between planets,usually within a singleplanetary system.

Remotely guided space probes have flown to all planets from Mercury to Neptune.

Examples: New Horizons,Dawn, the Voyager program and the Pioneer program.

In general, planetary orbiters and landers return much more comprehensive information than fly-by missions.

Probes have been placed into orbit around all possible five planetswhich have returned data about them and their natural satellites.

• Mars: Mars Pathfinder, Mars Global Surveyor, 2001 Mars Odyssey, Mars Reconnaissance Orbiter, MAVEN

• Venus: Mariner 2/5, Venera 4/5/6

• Jupiter: Galileo, Juno

• Saturn: Cassini/Huygens

• Mercury: Mariner 10, Messenger

INTERPLANETARY SPACEFLIGHT (CONTINUED)

The Apollo program has safelylanded 12 people on the Moon.

The American Vision for SpaceExploration, introduced byPresident George W. Bush had along-term goal to send humanastronauts to Mars.

But in 2010, President Obamaproposed for its cancellation.

NASA had proposed a manned fly-by mission of Venus in ’70s, butlater cancelled due to budget cuts.

Widely believed thatexploration gives knowledgethat can’t be gained byobservations from Earth'ssurface or the orbit.

Whether manned missionsmake a useful scientificcontribution is debatable.

Robotic probes are cheaperand safer, while astronauts canrespond more flexibly andintelligently to varied featuresof the exploration region.

HOW FAR HAS MAN GONE INTO SPACE?

The Apollo 11 astronautsNeil Armstrong and BuzzAldrin landed their LunarModule (LM) on July 20, 1969,and walked on the lunarsurface, thereby becoming thefirst persons to walk on acelestial object other thanthe Earth!

But is this really the furthesthumans had been to in space? Neil Armstrong on the Moon

HOW FAR HAS MAN GONE INTO SPACE?

(CONTINUED)

Well, technically, it ISN’T.

In April 1970, the crew ofNASA's ill-fated Apollo 13mission swung around the farside of the Moon at analtitude of 158 miles (254km), putting them 248,655miles (400,171 km) away fromEarth, when it was forced tomake an emergency return toEarth after an oxygen tankexplosion crippled thespacecraft.

This is the farthest ourspecies has ever been to,away from our planet.

Apollo 13 astronauts

HOW FAR HAVE UNMANNED SPACE PROBES

GONE INTO SPACE?

Till date, a number of crafts have either left the Solar System orhave been destined to do it at a future date.

The prime examples are the Pioneer 10, Pioneer 11, Voyager 2,Voyager 1 and New Horizons.

FURTHEST SPACE PROBES FROM EARTH

Probe LaunchedPrimary Mission

Future

Pioneer 10 1972Flyby of

Jupiter in 1973

Is heading towards Aldebaran, a giant star 65 light years away in Taurus

Pioneer 11 1973Flyby of

Jupiter (’74); Saturn (’79)

Is heading toward the constellation of Aquila,

northwest of Sagittarius

VoyagerProgram (1

& 2)

1977 (dual probe

launch)

Flyby of Jupiter, Saturn, Uranus,

and Neptune

Exploration of interstellar space

New Horizons 2006

Flyby of Jupiter (’07);

Pluto (July ’15)

Flyby of Kuiper belt (a region beyond the orbit of

Neptune) and beyond

VOYAGER 1

Part of the Voyager program,Voyager 1 launched by NASAon 1977, was announced onDec. 2011 to have reached theouter edge of Solar Systemand had entered inter-stellar space in August 2013.

Having operated for 39 years,Voyager 1 still communicateswith NASA’s Deep SpaceNetwork (DSN) to receivecommands and return data.

At a distance of 2.03×1010 km from the Sun as of September 2016, it is the farthest man-made object from Earth!

Artists impression of Voyager 1

VOYAGER 1 (CONTINUED)

On August 25, 2012, Voyager 1 crossed the heliopause to become the first spacecraft to enter interstellar space!

Will reach the Oort cloud in about 300 years and take about 30,000 years to cross it.

In about 40,000 years, it will pass within 1.6 light-years of the star Gliese 445, present in constellation Camelopardalis.

The ‘Voyager brothers’ are destined, perhaps eternally, to wander the Milky Way and be our messengers to the outer space…

INTERSTELLAR TRAVEL

Hypothetical piloted/ unpilotedtravel between stars, planetclusters or galaxies.

Distances between the planets inSolar System are below 30 AU.

Distances between stars aretypically hundreds ofthousands of AU, and usuallyexpressed in light-years.

Speeds required for it in ahuman lifetime far exceed whatcurrent methods of spacecraftpropulsion can provide.

Even with a hypotheticallyperfectly efficient propulsion,kinetic energy correspondingto those speeds is enormousby today's standards of energyproduction.

MODES OF TRAVEL (HYPOTHETICAL)

1. Slow, unmanned probes

2. Fast, unmanned probes (Near-light speed nano-spacecraft thrusters driven nano-probes that will use nanoparticles as propellant)

3. Slow, manned missions:

A. Generation ships: A type of ark in which the crew arriving at the destination is descended from those who started the trip.

B. Sleeper ships: Scientists/writers have postulated various techniques for this like human hibernation and cryonic preservation.

4. Fast, manned missions:

A. Time dilation: Journey by moulding the boundary of space-time.

B. Constant acceleration: If a propulsion system can produce acceleration continuously from departure to arrival, regardless of how it can be achieved, then it is the fastest method of travel!

MODES OF PROPULSION

Rocket concepts:

• Ion engine: Power is used to create charged particles of xenon,and accelerate them to extremely high velocities.

• Nuclear fission powered: Fission-electric, fission-fragment,nuclear pulse and nuclear fusion rockets.

• Antimatter rockets: Hypothetical use of antimatter for speeds.

Non-rocket concepts:

• Interstellar ramjets: A fusion rocket which would collect thediffuse hydrogen in interstellar space and use it as fuel.

• Beamed propulsion: A light/magnetic sail powered by amassive laser/particle accelerator in the home star system couldpotentially reach higher speeds than usual propulsion methods

PROPOSED PROJECTS FOR MANNED

MISSIONS

Primary target: Mars

NASA's Journey to Mars:Confirmed mission of visit &colonization of Mars by 2030aboard the Orion Multi-Purpose Crew Vehicle, aspacecraft intended to carryastronauts to locations at orbeyond Low Earth Orbit.

‘Mars One’ mission: Proposalfor human base on Mars by 2024by a group led by Bas Lansdorp,a Dutch entrepreneur.

Mars Colonial Transporter:SpaceX program to sendhumans to Mars in 2024 andthereafter begin colonization.

Proposed model of MCT by SpaceX

OUR PLACE IN THIS UNIVERSE

On a cosmic calendar that compresses the history of the Universe into one year, human civilization is just a few seconds old, and a human lifetime is a fraction of a second!!

In 1990, Voyager 1 had just completed its primary mission and was leaving the Solar System. It was commanded by NASA to turn its camera around and take one last photograph of Earth across a great expanse of space, at the request of astronomer & author, Carl Sagan.

The photograph of Earth thus taken on February 14, 1990, by the Voyager 1 from a distance of about 6 billion kilometres, as part of the Family Portrait series of images of the Solar System, came to be known as the PALE BLUE DOT in the scientific community.

Read more about it at en.wikipedia.org/wiki/Pale_Blue_Dot

The Pale Blue Dot Image (The Earth from 6 billion km away)

So aren’t we just too insignificant to matter

in the grand scheme of the universe?

Aren’t we just like hitch-hikers

in this vast road of space and time?

Earth is a very small stage

in the vast cosmic arena.

Make your time on it worthwhile

while you still have a go at it.

Think about it…

THANK YOU!

“The Earth is the only world known so far to harbour life.

There is nowhere else, at least in the near future,

to which our species could migrate.

Visit, yes. Settle, not yet.

Like it or not, for the moment,

the Earth is where we make our stand.”

- Carl Sagan, Cornell University, 1994

(During a public lecture on the Voyager program)

REFERENCES

Wikipedia

Official NASA Website

NASA Jet Propulsion Laboratory Website

Online Spitzer Images Library by Caltech University

Online Chandra X-Ray Observatory Library by Harvard University

Google Images