Deep ImpactFirst look inside a comet

Dr. Paul RocheFaulkes Telescope Project

Cardiff University

Overview

• Intro to Deep Impact• Comets in history• The modern comet• Why study them?• Deep Impact mission summary

Comets in history

Isaac Newton, 1680

“Dirty snowballs”

Nucleus

Coma

Tails : dust, gas

Water + molecules

The Modern Comet

Why study comets?

Formation of Solar system Impacts and mass extinctions Life in the universe?

Solar System History

>4.6 Gydark cloud

Planets accrete

HadeanOceans + rocks form~4.4 Gy ago

Late planetary bombardmentComets bring water + organicsArchean

Oldest life on Earth3.5-3.8 Gy ago

Death of the Dinosaurs

Climate & Civilisation

Tree-rings & ice-cores“Extreme climatic downturns”

2345 BC Bronze Age 1628 BC 1159 BC 540 AD Dark Ages

Dragon myths?

Deep Impact MissionSummary

Comet Uncertainties Density? What lies beneath surface? Chemistry? Aging processes?

Comet Aging

Build up of surface dust Lower albedo Large grains cannot leave Uneven surface jets Non gravitational acceleration

Mission Profile

• Geocentric Dist 0.89 AU• Heliocentric Dist 1.49 AU

Primary Goal Differences between

interior and surface Pristine Solar System

material Secondary Goal

Cratering physics Assess comet impact

hazard Calibrate crater record Comet evolution

• 360 kg impactor• 10.2 km/s

Approach & Encounter

Tempel-1Nucleus

Shield ModeAttitude through

Inner Coma

Science and Autonav Imaging to

Impact + 800 sec

ITM-1 StartE-88 min

ITM-2E-48 min

ITM-3E-15 min

Impactor ReleaseE-24 hours

TCA +TBD sec

AutoNav EnabledE-2 hr

Flyby S/CDeflection Maneuver

E-23.5 hr

2-wayS-band

Crosslink

500 km

Spacecraft Overview

InstrumentsMRI, ITS, HRI

Launch 12/1/05& First Light

Flyby Simulation

Ground Science Nucleus size and albedo Nucleus rotation Dust scattering properties

Dust / Gas evolution Education & Public Outreach program

Summary

Deep Impact mission – live and exciting science

Studying properties of cometsFirst views “below surface”FTN will participate in scientific research

programmeOpportunities for schools involvement