Download (Issue 6), June 2014

SUPARCO
ASTRONOMY &
ASTROPHYSICS
Newsletter
Volume 03, Issue 06
June 2014
PAKISTAN SPACE & UPPER ATMOSPHERE
RESEARCH COMMISSION
2014
contents
BULLETIN
Volume-03, June 2014
Pakistan’s Space Vision 2040, was
approved by the Prime Minister of
Pakistan which inter-alia included
augmentation / strengthening of
the Astronomy and Astrophysics
program of SUPARCO. SUPARCO`s
astronomy and astrophysics program
is mainly focused on theoretical and
observational research, for which an
astronomical observatory is planned
to be established. Research studies
pertaining to deep space objects
including galaxies, nebulae and
variable stars are also being initiated.
Search for earth-like planets is a hot
topic in astrophysics nowadays. It is
planned to conduct research studies
in this field also.
1)
Solar and Lunar Eclipses
Pg : 01
2)
Software Review
Pg : 04
3)
Events of the Month
Pg : 07
4)
Monthly Star Guide
Pg : 09
5)
Book Review
Pg : 07
6)
Monthly Science News
Pg : 11
Solar and Lunar
Eclipses
Out of all astronomical events, eclipses are the
most fascinating and eye-catching astronomical
events that occur almost every year and with
varieties. General public, including students,
media and other non- scientific communities
always place a great importance to eclipses.
Most of the people do not know about ‘behind
the scene’ happenings of eclipses and their
pleasure lie only in watching the phenomenon,
whereas amateur communities try to attempt
their best shots during an eclipse. Several myths
and stories are also very popular amongst the
oldies which describe eclipse as an indication
of something wrong to be happen in near
future. Similarly before the advent of science,
in dark ages, these phenomenons are think
of as a punishment or chastisement to the
Sun and Moon by their conceptual gods.
Apart from all this stuff we have in history, today
we define eclipse as “The obscuration of one
astronomical body by another which moves
between the first body and the observer”.
For example in case of solar eclipse, the body
which is obscured by another body, which is
moon, is the Sun and the observing place is at
Earth. Roughly we can say that an eclipse is the
alignment of the sun, moon and the Earth. In our
solar system, the relative positions of the Sun,
Moon, and Earth create solar eclipses and lunar
Page no. 01
eclipses but solar eclipses are particularly more
beautiful as they happen in day-time and being
observed by very large number of peoples.
The two main types of eclipses are solar
eclipse, in which the body obscured is the
Sun, and Lunar eclipse, in which moon the
obscured by the earth shadow. These two
types of eclipses are then further categorized
depending upon the appearance of the eclipse.
Solar eclipse can only occur at ‘New Moon’ when
the Moon passes between Earth and Sun. If the
Moon’s shadow happens to fall upon Earth’s
surface at that time, we see some portion of the
Sun’s disk covered or ‘eclipsed’ by the Moon. If
an eclipse is the alignment of the sun, moon and
earth then we should have a solar and a lunar
eclipse once in every month. Unfortunately,
this doesn’t happen because the Moon’s orbit
around Earth is tilted 5 degrees to Earth’s orbit
around the Sun. As a result, the Moon’s shadow
usually misses Earth as it passes above or below
our planet at New Moon. At least twice a year, the
geometry lines up just right so that some part of
the Moon’s shadow falls on Earth’s surface and
an eclipse of the Sun is seen from that region.
The geometry of the solar eclipse can be shown
as follows,
Total Solar Eclipse observed by SUPARCO officials at Bahawalpur HQ on 24th Oct, 1995
Annular Solar Eclipse:
The inner part of moon’s shadow is called
Umbral shadow and the outer part is known as
Unfortunately, not every eclipse of the Sun is
Penumral shadow.
a total eclipse. Sometimes, the Moon is too
small to cover the entire Sun’s disk. It occurs
Total solar eclipse occur when the Umbral part because the moon’s orbit around the Earth is
of the shadow sweeps across the Earth, then the not circular but is elliptical in shape. This causes
area which comes under the shadow sees the moon to come close and then move away while
total solar eclipse at that place. Places at earth remaining in its orbit. Because of this moon’s
surface which have total eclipse are joined by appears to change its apparent diameter in the
a line called path of totality. Total solar eclipse sky. When the moon is on the near side of its
therefore does not occur over a large population orbit and if an eclipse occurs at this time, it will
on earth (less than 1% on Earth surface) and to be a total eclipse. However, if an eclipse occurs
see a total solar eclipse one must be at the path while the Moon is on the far side of its orbit, the
Moon appears smaller than the Sun and can’t
of totality somewhere.
The total phase of a solar eclipse is very brief. completely cover it and during eclipse we see a
It rarely lasts more than several minutes. ring of solar disk in the sky.
Total Solar Eclipse:
Nevertheless, it is considered to be one of the
most awe inspiring spectacles in all of nature.
The sky takes on an eerie twilight as the Sun’s
bright face is replaced by the black disk of the
Moon. Surrounding the Moon is a beautiful
gossamer halo. This is the Sun’s spectacular
solar corona; a super heated plasma two million
degrees in temperature. The corona can only be
seen during the few brief minutes of totality.
2005 Annular Solar
Page no. 02
Partial Solar Eclipse:
When both the above mentioned conditions
not fulfilled, we still get another case of solar
eclipse which is known as partial solar eclipse.
This occurs when only the penumbral part of
moon’s shadow sweeps across the earth surface.
In such eclipses only a small portion of the Sun
is covered by the moon’s shadow.
Because solar eclipses are the result of periodic
motion of the Moon about the Earth, there are
regularities in the timing of eclipses that give
cycles of related eclipses. These cycles were
known and used to predict eclipses long before
there was a detailed scientific understanding of
what causes eclipses. For example, the ancient
Babylonians understood one such set of cycles
Partial solar Eclipse observed at SUPARCO
HQ, on 5th Jan, 2011
Eclipses of the Sun: 2012 - 2015
Calendar Date
Eclipse Type
Central Duration
2012 May 20
Annular
05m46s
2012 Nov 13
Total
04m02s
2013 May 10
Annular
06m03s
2013 Nov 03
Hybrid
01m40s
2014 Apr 29
Annular
2014 Oct 23
Partial
2015 Mar 20
Total
02m47s
2015 Sep 13
Partial
0.787
Page no. 03
Geographic Region of Eclipse Visibility
Asia, Pacific, N. America
[Annular: China, Japan, Pacific, w U.S.]
Australia, N.Z., s Pacific, s S. America
[Total: n Australia, s Pacific]
Australia, N.Z., c Pacific
[Annular: n Australia, Solomon Is., c Pacific]
Americas, s Europe, Africa
[Hybid: Atlantic, c Africa]
Indian, Australia, Antarctica
[Annular: Antarctica]
Pacific, N. America
Iceland, Europe, n Africa, n Asia
[Total: n Atlantic, Faeroe Is, Svalbard]
s Africa, s Indian, Antarctica
called the Saros, and were able to predict
eclipses based on this knowledge.
Though the solar eclipses are very interesting
to watch, special care must be taken while
observing a solar eclipse. Filters, special eclipse
goggles should be used to watch lunar eclipse.
Second kind of eclipses that we have is known
as Lunar Eclipses in which the moon is obscured
by the shadow of earth. Following diagram
shows the geometry of a lunar eclipse,
Taking this picture into account three different
types of lunar eclipses are defined,
Penumbral lunar eclipse
Partial lunar Eclipse
Total lunar Eclipse
The first one is of no importance to general
public and has its interest only to academics as
it is hard to perceive that the moon is in eclipse.
This is because the penumbral shadow of the
earth is very faint and when the moon comes
under this shadow its glare only slightly reduces
which is hard to observe. Partial lunar eclipse
occurs when a portion of moon passes through
the earth’s umbral shadow. When this partial
dipping of moon into earth shadow converts
into full what is observed is called a total lunar
eclipse.
When a partial lunar eclipse is going on, the
curved shadow of Earht is apparent on the
Moon’s face; the Moon looks like in a crescent
phase, but the terminator line (the line between
light and dark) is not curved the same way.
When a total lunar eclipse is happening, the
entire Moon is in Earth’s shadow, and the Moon
looks full, but glows only faintly red.
Lunar eclipses tend to last for several hours, from
beginning to end. Totality—the time when the
Moon is in the darkest part of Earth’s shadow,
and Earth blocks all direct sunlight onto the
Moon—usually lasts for the better part of an
hour. Any given lunar eclipse can be seen from
everywhere on the planet where it is nighttime.
Earth’s atmosphere is dense enough to act a
little bit like a lens, so it refracts a small amount
of sunlight shining through it toward the Moon.
This small fraction of light, which is mostly red
because that is the color of light that refracts
best, bounces off the Moon’s surface and
comes back to Earth. Before and after totality,
the direct sunlight reflected off the Moon is so
strong by comparison that it drowns out this
refracted light, so we normally cannot see it
with our unaided eyes. During totality, however,
the Earth-atmosphere-refracted light is quite
visible as a soft reddish glow.
Eclipses of the Moon: 2012 - 2015
Calendar Date
Eclipse Type
Central Duration
2012 Jun 04
Partial
02h07m
2012 Nov 28
Penumbral
-
2013 Apr 25
Partial
00h27m
2013 May 25
Penumbral
-
Americas, Africa
2013 Oct 18
Penumbral
-
Americas, Europe, Africa, Asia
2014 Apr 15
Total
2014 Oct 08
Total
2015 Apr 04
Total
2015 Sep 28
Total
03h35m
01h18m
03h20m
00h59m
03h29m
00h05m
03h20m
01h12m
Geographic Region of Eclipse Visibility
Asia, Aus., Pacific, Americas
Europe, e Africa, Asia, Aus., Pacific, N.A.
Europe, Africa, Asia, Aus.
Aus., Pacific, Americas
Asia, Aus., Pacific, Americas
Asia, Aus., Pacific, Americas
e Pacific, Americas, Europe, Africa, w Asia
Page no. 04
Total Solar Eclipse observed by SUPARCO
Page no. 05
sOFTWARE rEVIEW
Google Moon
Google Moon is a service similar to Google
Earth that shows satellite images of the Moon.
It was launched by Google on July 20, 2009,
the 40th anniversary of the Apollo 11 lunar
landing. The landing site of each of the Apollo
missions is shown on the satellite image,
providing more information on each mission as
the user zooms in. The first version of Google
Moon only included low-resolution satellite
imagery of the entire Moon, and when zoomed
in too close, a Swiss cheese pattern would
appear. The Swiss cheese pattern was used for
the closest zoom levels before high-resolution
images became available.
The current version of Google Moon has three
modes,
1.
Apollo mode
Apollo provides information about each of the
Apollo missions, including place marks, maps,
images, video, and Street View-style panoramas,
all provided by NASA.
2.
Visible mode
This mode provides the satellite imagery for the
Moon, provided by the Clementine mission.
3.Elevation
This shows a false color rendering of the Moon’s
elevation.
A Charts layer is also available. This shows
Apollo-era geologic and topographic charts for
certain areas of the Moon’s surface.
Google Earth 5 includes a separate globe
of the moon, starting on July 20, 2009 to
commemorate the 40th anniversary of the
Apollo 11 Moon landing. The maps are of a
much higher resolution than those on the
browser version of Google Moon and it also
includes 3D renderings of the Moon terrain.
Page no. 06
Events of the month
(june 2014)
Celestial Events for the Month of June, 2014
June 7 - Conjunction of the Moon and Mars:
The Moon will pass within two degrees of the planet Mars in the evening sky. The gibbous moon
will be at magnitude -12.2 and Mars will be at magnitude -0.8. Look for both objects in the western
sky just after sunset. The pair will be visible in the evening sky for about 6 hours after sunset.
June 13 - Full Moon:
The Moon will be directly opposite
the Earth from the Sun and will
be fully illuminated as seen from
Earth. This phase occurs at 04:11
UTC. This full moon was known
by early Native American tribes
as the Full Strawberry Moon
because it signaled the time of
year to gather ripening fruit.
It also coincides with the peak
of the strawberry harvesting
season. This moon has also
been known as the Full Rose
Moon and the Full Honey Moon.
Page no. 07
June 21 - June Solstice:
The June solstice occurs at 10:51 UTC. The North Pole of the earth will be tilted toward the Sun,
which will have reached its northernmost position in the sky and will be directly over the Tropic
of Cancer at 23.44 degrees north latitude. This is the first day of summer (summer solstice) in the
Northern Hemisphere and the first day of winter (winter solstice) in the Southern Hemisphere.
June 28 – New Moon:
The Moon will be directly between the Earth and the Sun and will not be visible from Earth. This
phase occurs at 08:08 UTC. This is the best time of the month to observe faint objects such as
galaxies and star clusters because there is no moonlight to interfere.
Page no. 08
Monthly Star
Guide (June)
Nights are at their shortest and days at their longest in northern latitudes in
June, and vice versa in the southern hemisphere. In the far north, twilight is
now permanent throughout the night, while the winter skies f the south are
dominated by a band of prominent constellations lying in the Milky Way.
Northern Latitudes:
Looking North
Ursa Minor (the little Bear) stands on its tail, and Draco arches above the
north celestial pole, marked by the Polaris. The plough (or Big Dipper) is high
in the northwest. Towards the east, the starts that from the summer Triangle
are in view: Vega, Deneb in Cygnus, and Alter in Aquila (far left of looking
South map).
Page no. 09
Looking South
Hercules is high in the south-east, with Vega to its left and Arcturus in Bootes, to its right. Ophiuchus, Virgo, and both halves of Serpenns are below them. Antares, in Scorpius, glints red above
the southern horizon, the faint stars of Libra to its right. Leo is setting in the west.
Page no. 10
monthly science news
HADES searches for dark
matter: Astrophysicists
cross ‘Dark Photon’ off the
list in top position
Although Dark Energy and Dark Matter appear
to constitute over 95 percent of the universe,
nobody knows of which particles they are made
up. Astrophysicists now crossed one potential Dark
Matter candidate -- the Dark Photon or U boson -- off
the list in top position. This is the result of recent HADES experiments, where researchers from the Helmholtz-Zentrum Dresden-Rossendorf
(HZDR) and from 17 other European institutes try to pin down the nature of Dark Matter.
A turbulent birth
for stars in merging
galaxies
Using state of the art computer simulations,
a team of French astrophysicists have for the
first time explained a long standing mystery:
why surges of star formation (so called
‘starbursts’) take place when galaxies
collide. The scientists, led by Florent Renaud
of the AIM institute near Paris in France, publish their results in a letter to the journal Monthly
Notices of the Royal Astronomical Society. Astronomers create
first realistic virtual
universe
Move over, Matrix -- astronomers have
done you one better. They have created
the first realistic virtual universe using a
computer simulation called “Illustris.” Illustris
can recreate 13 billion years of cosmic evolution in a cube 350 million light-years on
a side with unprecedented resolution.
Page no. 11
Ancient crater points to
massive meteorite strike
The discovery of an ancient ring-like structure in
southern Alberta suggests the area was struck
by a eteorite large enough to leave an eightkilometre-wide crater, producing an explosion
strong enough to destroy present-day Calgary, say
researchers from the Alberta Geological Survey
and University of Alberta. Nearest bright
‘hypervelocity star’ found:
Speeding at 1 million
mph, it probes black hole
and dark matter
A University of Utah-led team discovered a
“hypervelocity star” that is the closest, secondbrightest and among the largest of 20 found so
far. Speeding at more than 1 million mph, the star
may provide clues about the supermassive black
hole at the center of our Milky Way and the halo of
mysterious “dark matter” surrounding the galaxy,
astronomers say. NASA’s Curiosity
rover drills
sandstone slab on
Mars
Portions of rock powder collected
by the hammering drill on NASA’s
Curiosity Mars rover from a slab of Martian sandstone will be
delivered to the rover’s internal
instruments. Page no. 12
R
OSPHERE RE
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AR
AN
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June -
2014
N
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NVeoluwmse-3l , Issue 4
CO M M I S S I O
S PA C E & U P
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Designed by: Aley Ali Naqvi
Contact Information
SPAS Directorate
Gulzar-e-Hijri SUPARCO Road
Sector 28, SUPARCO, Karachi, Pakistan
Tel: 021-34690765-74
Fax 021-34690795
Email: [email protected]
SUPARCO - ASTRONOMY &
ASTROPHYSICS Bulletin is a
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