Iraq News Now

The American space agency's InSight lander appears to have

detected its first seismic event on Mars.
The faint rumble was

picked up by the probe's sensors on 6 April - the 128th Martian day, or sol, of

the mission.
It is the first

seismic signal detected on the surface of a planetary body other than the Earth

and its Moon.
Scientists say the

source for this "Marsquake" could either be movement in a crack

inside the planet or the shaking from a meteorite impact.
Nasa's

InSight probe touched down on the Red Planet in November last year.
It aims to identify

multiple quakes, to help build a clearer picture of Mars' interior structure.
Researchers can then

compare this with Earth's internal rock layering, to learn something new about

the different ways in which these two worlds have evolved.
Interestingly,

InSight's scientists say the character of the rumble reminds them very much of

the type of data the Apollo sensors gathered on the lunar surface.
Astronauts installed

five seismometers that measured thousands of quakes while operating on the Moon

between 1969 and 1977.
InSight's

seismometer system incorporates French (low-frequency) and British

(high-frequency) sensors. Known as the Seismic Experiment for Interior

Structure (SEIS), this instrument was lifted on to the Martian surface by the

probe's robotic arm on 20 December.
Both parts of the

system observed the 6 April signal, although it wasn't possible to extract any

information to make a more definitive statement about the likely source or the

distance from the probe to the event.
"It's probably

only a Magnitude 1 to 2 event, perhaps within 100km or so. There are a lot of

uncertainties on that, but that's what it's looking like," said Prof Tom

Pike, who leads the British side of the seismometer package.
On Earth, very few

people would notice a Magnitude 1 to 2 event.
The team is

investigating three other signals picked up only by the low-frequency sensors -

on 14 March (Sol 105), 10 April (Sol 132) and 11 April (Sol 133). However,

these were even smaller than the Sol 128 event, and the InSight scientists do

not have the confidence yet to claim them as real seismic events.
The probe's prime

mission is set to run for two Earth years - a little more than one Martian

year.
Given the time taken

to make this first detection, it might suggest InSight should record another

dozen or so seismic signals in the initial operating period, explained Prof

Pike.
"When you've

got one, you don't know whether you were just lucky, but when we see two or

three we will have a better idea.
"Of course, if

the other three are confirmed then we could be looking at quite a large number

of detections over the next two years," the Imperial College London

researcher said.