networking ground-based optical telescopes for space guard missions

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Networking ground-based optical telescopes for spaceguard missions

Hakim Luthfi Malasan

Bosscha Observatory & Astronomy Division, FMIPA, ITB

Earth in solar system,

NEO-NEA-ECA-PHA-...

Apollo 17 (7-19 DECEMBER 1972)

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New look at our solar system


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Asteroid Belt


Asteroids with diameters > 250 km

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Asteroid Founder in Diameter (km)

1 Ceres Piazzi 1801 974

2 Pallas Olbers 1802 544

4 Vesta Olbers 1807 529

10 Hygiea de Gasparis 1849 407

31 Euphrosyne Ferguson 1854 370

704 Interamnia Cerulli 1910 350

511 Davida Dugan 1903 323

65 Cybele Tempel 1861 309

52 Europa Goldschmidt 1858 289

451 Patientia Charlois 1899 276

15 Eunomia de Gasparis 1851 272

3 Juno Harding 1804 267

16 Psyche de Gasparis 1852 250

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Seminar Sains Antariksa V, Serpong

Near-Earth Asteroids (NEAs) • NEA diameters known: 13 with diameters > 250 km 811 with diameters > 1 km ~100,000 with diameters > 0.14 km • Meteor (shooting star): usually comet dust burning in Earth’s atmosphere. • Meteorite: reaches Earth’s surface, usually from asteroid belt. Mass: few kilogram to many tons. • 100-ton meteorite has impact energy of ~1 megaton TNT (~70 x Hiroshima). • On Earth: ~170 impact craters, diameters of ~10 to ~300 km: explosions up to 100,000 Gigaton TNT in the past. • Present chance for heavy impact: ~1 in 1 000 000 / yr. • Barringer meteorite: 50 000 years ago, 13 km/s, diameter ~50 m, mass ~300 000 ton, explosion of ~2.5 megaton TNT.

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Motivations

Two major events can be identified as the causes of such enlarged attention:

• The correlation between the impacts of minor bodies on our planet and global catastrophes;

• The evidence given to such type of cosmic events by the impact of the periodic comet Shoemaker-Levy 9 with the planet Jupiter in July 1994.


http://upload.wikimedia.org/wikipedia/commons/f/f3/InnerSolarSystem-en.png

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IMPACTS

When d (asteroid) Crater d (Crater) E (TNT)

65 Myear BC 10 ± 4 km Chicxulub, Mexiico

180-300 km 108 MT

50 Kiloyear BC ~40 m Barringer, USA 1.2 km 2.5 MT

1490 meteorite fall 1-1.5 kg

Shani, China - >10,000 people †

1908 40 ± 10 m Tunguska, R [2000 km2] 10-15 MT

1947 Meteorite fall Sikhote Alin, R 1m -26 m

Hiroshima 15 kiloT

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Chicxulub, Yucatán, Mexico (D = ~265 km, t = 65 Myr)

Barringer Meteor Crater

Arizona, USA (D = 1.2 km, t = 50 000 yr)

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10-km NEO

resulted in total

extinction of about

half the living

species

of animals and

plants

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Terrestrial impact structures

• Nearly 200 have been established with a high degree of certainty


Spaceguard,

spacewatch, Near-

earth objects

awareness program…

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Spacewatch project (Lunar and planetary laboratory, Univ. of Arizona)

• Discovery and followup of asteroids and comets

• First to use CCD for solar system astrometry

• Continuous operation since 1984

• Detection statistics have supported studies of:

– NEOs

– Centaurs

– Main belt

– TNOs


Spaceguard Survey Progress

• Originally proposed by NASA panel in 1992 Additional support from US Congress in 1995

Adopted as NASA goal in 1998 (in collaboration with USAF)

• Objective: Discover and track 90% of the Near Earth Asteroids (NEAs) with diameter greater than 1 km within ten years (by 2008) Estimated number of NEAs larger than 1 km: approximately 900

Number discovered through end of 2000: approximately 430

Estimated completion date (to 90%): 2012

• Most NEAs discovered by MIT-Lincoln Lab LINEAR search system Two USAF 1-m telescopes with NASA operating funds

Discovery rate approximately 5 / month

• International program for follow-up and orbit determination

• Threatening NEAs (if any) should be identified decades before impact


Technical characteristics..

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Instrumental requirements

• Discovery instruments D 1-m. At least two such instruments in each hemisphere, well separated in longitude, plus possible back-up instruments.

• The Field of view (FOV) of these instruments should be of several square degrees and paved with fast read-out CCDs.

• The discovery sites should have large storage capabilities in order to retain all frames taken during the sky survey. These images should, after a first processing for detecting new objects, be transferred to an ad hoc data center for further inspection and for documentation useful for non-NEO studies.

• The discovery centers should be sufficiently co-ordinated, in order not to duplicate efforts.


• Follow-up instruments may be of any class, but at least two telescopes in the 2m range are needed for follow-up of faint objects, one in each hemisphere. Moreover, sufficient observing time should be allocated at larger instruments (in the 4m class) for follow-up of very faint objects, when the necessity arises.

• More professional centers should be involved in follow-up observations. The follow-up centers must be efficiently co-ordinated at a high level, including planning of observations, recovery strategies, sharing of schedules, joint campaigns.



Bisei Spaceguard Center,

Bisei Town, Okayama Prefecture,

JAPAN

Large Optical Telescope

The large optical telescope, the primary

mirror of which has a diameter of 1 meter,

permits observation over a wide range of 3

degrees. A cooled charge-coupled device

(CCD) camera consisting of 10 highly

sensitive CCD elements arranged in a

mosaic pattern is installed at the focal point

of the telescope. A batch of digital image data

acquired by the camera is sent to computers

where it is analyzed. The telescope can

detect space debris of about 50 cm in

diameter near the GEO and GTO, and NEOs

of at least 1 km in diameter.

Focus mode Cassegrain-type focusing, F/3

Field of view 3 degrees

Max. tracking speed

More than 5 deg./sec (right ascension/declination)

Structure Folk-type equatorial

CCD camera Approx. 160-mm imaging diameter Uses ten of 2,000 x 4,000 pixel CCD cell

CCD temperature

Approx. 173K during observations

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Small Tracking Telescope

The two small telescope, which

have primary mirror of 50 cm

and 25 cm co-mounted on 50-

cm telescope, are principally

used to track and observe

space debris travelling at high

speed. For this season, each

telescope is mounted in a

structure designed to enable

the telescope tube to be

moved at a rate of 5 degrees

per second. As with the large

telescope, a cooled CCD

camera is used to acquire

image data which is analyzed

by computer in order

determine the orbit of the

space debris and NEOs.

50-cm Optical Telescope

25-cm Optical Telescope

Focus mode Cassegrain-type focusing, F/2

Baker Richey Chretian-type focusing, F/5

Field of view 2 degrees 5 degrees

Max. tracking speed More than 5 deg./sec (right ascension/declination)

ditto (Mount on 50-cm Optical Telescope)

Structure Folk-type equatorial ditto (Mount on 50-cm Optical Telescope)

CCD camera Approx. 50-mm imaging diameter Uses two of 2,000 x 4,000 pixel CCD cell

2,000 x 2,000 pixel CCD cell

CCD temperature Approx. 173K during observations

Approx. 243K during observations

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http://www.spaceguard.or.jp/bsgc_jsf/pamphlet/05opt.jpg

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Computer System and LAN

The proposed computer system and

LAN for the Bisei Spaceguard Center

are shown at right. The large and small

telescopes are operated by computer

control. In addition, not only is it

possible to transmit observation data

from the facility to other stations, the

telescopes can also be controlled

externally.

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Observational and reduction techniques

Moving object detection program

Stacking method

Hough transform

…


Can we participate in

the spaceguard

missions?

Observing network operation


Northern hemisphere:

Italy, Japan, USA

Southern hemisphere:

Uruguay, Australia

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Small telescopes v.s.

Large telescope?

Networking observatories with “small”

telescopes

Astroeconomics model toward higher

productivity of (optical) data


Astroeconomic model of network (Budding 1993) Cost-productivity for

group of telescopes

(characterized by D)

in remote/automated

fashion

1. Information flow

2. Key cost & organization

Advantages of small telescope: Efficiency

Adequacy Availability Flexibility

Serendipity

low capital

High capital

Relative knowledge rate WET

AAVSO


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Role of general-purpose small telescopes

(small telescope owner’s view)

• Projects which require large number of observations

• Projects which require all-sky or extended time coverage

• Projects which require extreme flexibility

• Stimulation for larger access ability to larger telescope

• Training, experiment & development of (new) instrument

• Education


Proliferation of small telescopes at the Observatory and new public facility

Almost 40

telescopes with

20-28 cm are

available on

market and

owned by LAPAN,

BMKG, ITB and

other institutes


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Extending capability of small-

intermediate size telescopes for

networking

Support of pointing & tracking for proper CCD imagery & spectroscopy

Autoguider

New control system based on common S/W Remote

Embedded acquistion system


Existing network of sites for small telescope (main

players: ITB, LAPAN, BMKG, supporters:

Kemenkominfo, Kemdiknas)


Spaceguard integrated system

Leading institutions: LAPAN, BMKG, ITB

• A ground-based observational system, including all observation stations for discovery, follow up and physical studies

• A space-based observational system, devoted to physical characterization and discovery and tracking of peculiar objects

• A ground network, composed by the data collecting and analysis centers


The Necessity of International Cooperation

The problem is thus international in scope; it is also international in solution.

The need for international cooperation is obvious, and rapid and efficient international communication

through a central agency is a requirement.


That the hazard posed by NEO's is a problem for all

humankind hardly needs repeating.

The likelihood of a particular spot being the target of an

impact is independent of its geographic position, so that

we are all equally at risk.

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* IAU Minor Planet Center, hosted at SAO

* IAU Division III Working Group on

Small Bodies Nomenclature

* IAU EC Advisory Committee on

Hazards of Near-Earth Objects

* IAU web page <http://www.iau.org/public/nea/>

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The role of the International Astronomical Union (IAU)


The IAU Executive Committee is invited to consider

Reviewing the role of the current IAU EC Advisory Committee (AC) on Hazards of Near Planetary Objects.

Creating a new IAU EC Working Group on Hazards of Near Earth Objects. Assigning one IAU (GA-)Symposium or GA-Special Session per three years to

Near Earth Objects hazards science, to be organized by the suggested new EC Working Group on Hazards of Near Earth Objects.

Calling upon its 67 IAU National Members to increase their support for astronomical observatories participating in surveys for detection, tracking and monitoring of Near Earth Objects down to D > 25 m (i.e., H < 26 mag). Such could perhaps be framed by the EC in a Resolution for the IAU XXVIII General Assembly in Beijing, August 2012.

Pro-active collaboration with other scientific unions and institutions with an interest in the risks of Natural Hazards and Disasters, particularly with the recently established International Council for Science (ICSU) programme on Integrated Research on Disaster Risk.


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IAU WEB PAGE on NEAs

The International Astronomical Union (IAU) reports the launch in March 2010 of its public web page on Near Earth Asteroids, entitled

"Near Earth Asteroids (NEAs) A Chronology of Milestones" <www.iau.org/public/nea/>

The page quotes facts related to Near Earth Asteroids for the period AD 1800 to AD 2200 from the available literature and web sites: discoveries, close encounters within 1 Lunar Distance (quoted from JPL), and related scientific meetings and reports.


TERIMA KASIH

...since the Moon has always been the companion of the Earth,

the history of the former is only a paraphrase of the history of

the latter... [Its mirror on Earth] contains a disturbing factor.

There is no assurance that these meteoritic impacts have all

been restricted to the past. Indeed we have positive evidence

that [sizeable] meteorites and asteroids still abound in space

and occasionally come close to the Earth. The explosion that

formed the [lunar] crater Tycho...would, anywhere on Earth, be

a horrifying thing, almost inconceivable in its monstrosity. (Baldwin 1949)


networking ground-based optical telescopes for space guard missions

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